# Patent

## Title
Method and system of monitoring emergency vehicles

## Abstract

A method of monitoring emergency vehicles includes generating host vehicle information with a navigation unit, the host vehicle information including a host vehicle location and a host vehicle heading, receiving emergency vehicle information with a receiver, the emergency vehicle information including an emergency vehicle emergency status, an emergency vehicle location and an emergency vehicle heading, determining with a controller a distance between the host vehicle location and the emergency vehicle location, determining with the controller whether the distance between host vehicle and the emergency vehicle is decreasing, and performing a mitigation operation, when the distance between host vehicle and the emergency vehicle is decreasing, and the distance between host vehicle and the emergency vehicle is a threshold distance or less.

## Background
BACKGROUND
Field of the Invention
The present invention generally relates to a method and system of monitoring emergency vehicles. More specifically, the present invention relates to a method and system disposed in a host vehicle that provides emergency vehicle information so as to improve vehicle safety and enable the driver of the host vehicle to abide by local jurisdictional requirements in enabling emergency vehicles to travel unabated.
Background Information
In recent years, vehicles have become more equipped with features for improving safety. For example, vehicles can be equipped with a contact warning system that identifies the location of the vehicle and the locations of other nearby vehicles to determine whether the vehicle may come into contact with any of the other vehicles. These systems generally include sensors that detect the location and proximity of vehicles and objects relative to a host vehicle and warn the driver of the host vehicle of possible contact with the vehicle or object. Some systems can alter the speed or trajectory of the host vehicle in attempting to avoid contact.
SUMMARY
It has been discovered that emergency vehicles may require advanced warning to maintain the proper distances between a host vehicle and an emergency vehicle. Moreover, it is apparent that the jurisdictional requirements regarding emergency vehicles may vary in different states or cities, and thus, the requirements may be unknown to the driver of the host vehicle. In view of the state of the known technology, one aspect of the present disclosure is to provide a mitigation operation to a host vehicle when an emergency vehicle is approaching. In one disclosed embodiment, a method of monitoring emergency vehicles comprises generating host vehicle information with a navigation unit, the host vehicle information including a host vehicle location and a host vehicle heading, receiving emergency vehicle information with a receiver, the emergency vehicle information including an emergency vehicle emergency status, an emergency vehicle location and an emergency vehicle heading, determining with a controller a distance between the host vehicle location and the emergency vehicle location, determining with the controller whether the distance between host vehicle and the emergency vehicle is decreasing, and performing a mitigation operation, when the distance between host vehicle and the emergency vehicle is decreasing, and the distance between host vehicle and the emergency vehicle is a threshold distance or less.
These and other objects, features, aspects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses an embodiment of the present invention.



BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the attached drawings which form a part of this original disclosure:
FIG. 1 is a block diagram illustrating an example of a vehicle equipped with a emergency vehicle monitoring system according to embodiments disclosed herein in relation to an emergency vehicle and components of a wireless communication network;
FIG. 2 is an example of a vehicle equipped with an emergency vehicle monitoring system according to embodiments disclosed herein;
FIG. 3 is a partial interior view of the passenger compartment of a vehicle equipped with an emergency vehicle monitoring system according to embodiments disclosed herein;
FIGS. 4A and 4B are flowcharts illustrating exemplary operations for determining the mitigation operation of the emergency vehicle monitoring system according to disclosed embodiments;
FIG. 5 is a graph illustrating an example of a four quadrant coordinate system which shows an example of a location of an emergency vehicle within the first quadrant with respect to a location of the host vehicle which is at the center of the coordinate system;
FIG. 6 is a graph illustrating an example of a location of an emergency vehicle within the second quadrant of the four quadrant coordinate system with respect to a location of the host vehicle which is at the center of the coordinate system;
FIG. 7 is a graph illustrating an example of a location of an emergency vehicle within the third quadrant of the four quadrant coordinate system with respect to a location of the host vehicle which is at the center of the coordinate system;
FIG. 8 is a graph illustrating an example of a location of an emergency vehicle within the fourth quadrant of the four quadrant coordinate system with respect to a location of the host vehicle which is at the center of the coordinate system; and
FIGS. 9 through 14 are exemplary diagrams illustrating different scenarios that are handled by the emergency vehicle monitoring system according to disclosed embodiments.



DETAILED DESCRIPTION OF EMBODIMENTS
Selected embodiments will now be explained with reference to the drawings. It will be apparent to those skilled in the art from this disclosure that the following descriptions of the disclosed embodiments are provided for illustration only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
FIG. 1 is a block diagram illustrating a host vehicle (HV) 10 that is equipped with an emergency vehicle monitoring system 12 according to a disclosed embodiment. The emergency vehicle monitoring system 12 communicates with at least one emergency vehicle 14 (EV). The emergency vehicle 14 can include a type of two-way communication system that is capable of communicating information about at least the location, speed, status and direction of the emergency vehicle 14 as understood in the art.
The emergency vehicle monitoring system 12 of the host vehicle 10 and the emergency vehicle 14 can communicate with a two-way wireless communications network. The two-way wireless communications network can include one or more global positioning satellites 16 (only one shown) and one or more roadside units 18 (only one shown) that send and receive signals to and from the emergency vehicle monitoring system 12 of the host vehicle 10 and the emergency vehicle 14.
Turning to FIG. 2, an emergency vehicle monitoring system 12 for a host vehicle 10 is illustrated in accordance with one embodiment. The emergency vehicle monitoring system 12 includes a controller 20, a navigation unit 22, a receiver 24, a warning indicator 26 or system, a feedback unit 28 and a haptic feedback device 30.
The controller 20 preferably includes a microcomputer with a control program that controls the emergency vehicle monitoring system 12 as discussed below. The controller 20 can also include other conventional components such as an input interface circuit, an output interface circuit, and storage device(s) 20a such as a ROM (Read Only Memory) device and a RAM (Random Access Memory) device. The microcomputer of the controller 20 is programmed to control one or more of the navigation unit 22, the warning indicator 26 or system, the feedback unit 28 and the haptic feedback device 30, and to make determinations or decisions, as discussed herein. The memory circuit stores processing results and control programs, such as ones for the navigation unit 22, the warning indicator 26 or system, the feedback unit 28 and the haptic feedback device 30 operation that are run by the processor circuit. The controller 20 is operatively coupled to the navigation unit 22, the warning indicator 26 or system, the feedback unit 28 and the haptic feedback device 30 in a conventional manner, as well as other electrical systems in the vehicle, such the turn signals, windshield wipers, lights and any other suitable systems. Such a connection enables the controller 20 to monitor and control any of these systems as desired. The internal RAM of the controller 20 stores statuses of operational flags and various control data. The internal ROM of the controller 20 stores the information for various operations. The controller 20 is capable of selectively controlling any of the components of the emergency vehicle monitoring system 12 in accordance with the control program. It will be apparent to those skilled in the art from this disclosure that the precise structure and algorithms for the controller 20 can be any combination of hardware and software that will carry out the functions of the present invention.
As shown in FIG. 2, the controller 20 can include or be in communication with user input devices 20b. The user input devices 20b can include, for example, a human-machine interface (HMI) which enables a user (e.g., the driver and/or passenger) to interact with the emergency vehicle monitoring system 12 as understood in the art and discussed herein. The controller 20 can further include or be in communication with one or more storage device(s) 20a which can store information as discussed herein.
The emergency vehicle monitoring system 12 may include a navigation unit 22, such as a GPS 32. In one embodiment, the host vehicle 10 receives a GPS satellite signal. As is understood, the GPS 32 processes the GPS satellite signal to determine positional information (such as location, speed, acceleration, yaw, and direction, just to name a few) of the host vehicle 10. As noted herein, the navigation unit 22 is in communication with the controller 20, and is capable of transmitting such positional information regarding the host vehicle 10 to the controller 20.
The navigation unit 22 also can include a storage device 34 that stores map data. Thus, in determining the position of the host vehicle 10 using any of the herein described methods, devices or systems, the positioning of the host vehicle 10 may be compared to the known data stored in the storage device. Thus, the emergency vehicle monitoring system 12 may accurately determine the location of the host vehicle 10 on an electronic map. The storage device 34 may also store any additional information including the current or predicted vehicle position and any past vehicle position/route or any other suitable information.
The emergency vehicle monitoring system 12 may include a receiver 24. The receiver 24 can be any suitable receiver 24 that is capable of receiving data or information wireless from an emergency vehicle 14 or other suitable source.
The emergency vehicle monitoring system 12 may include a warning indicator 26. As shown in FIG. 3, the warning indicator 26 may include a mitigation operation that would facilitate the operator of the host vehicle 10 in avoiding contact or interference with the travel of the emergency vehicle 14. In one example, the mitigation operation can be visual warning and/or an audio output warning. For example, the warning indicator 26 may include a visual display or light indicator that flashes or illuminates the instrument cluster on the instrument panel 38 of the host vehicle 10, activates a heads-up display 40, is a visual readout 42 in an information display unit 44, is an audible noise emitted from a speaker 36, or any other suitable visual display or audio or sound indicator or combination thereof that notifies the driver or interior occupant of the host vehicle 10 that an emergency vehicle 14 has been detected and the host vehicle 10 may require an action to avoid interfering with the travel of the emergency vehicle 14. As shown specifically in FIG. 3, both the heads-up display 40 and the information display unit 44 show a visual warning of “Emergency Vehicle Detected”.
As shown in FIGS. 2 and 3, the feedback unit 28 may include a mitigation operation, such as tactile feedback generated by the haptic feedback device 30 that can be a vibration actuator in the steering wheel, the driver seat, or any other suitable location within the host vehicle 10. That is, the mitigation operation can include providing haptic feedback to a portion of an interior of the host vehicle 10 located proximate to the driver. For example, the mitigation operation may be a feedback force within the steering system 46 that notifies the driver that the steering wheel 48 should be turned in a specific direction. Such a mitigation operation does not necessarily need to alter the trajectory of the vehicle but may be a minor turn of the steering wheel 48 simply to notify the driver that a steering wheel operation is necessary. Thus, in one embodiment, the mitigation operation can include visual or auditory notification of the presence of an emergency vehicle 14 and a slight turning of the steering wheel 48 to indicate that the trajectory of the host vehicle 10 should be altered to avoid interfering with the operation of the emergency vehicle 14. The feedback unit 28 is connected to the controller 20, which is programmed to operate the feedback unit 28 to warn the driver or control the vehicle.
Additionally, the feedback unit 28 may also be connected to the steering system 46 of the host vehicle 10, such that the controller 20 can control the steering system 46 of the host vehicle 10. Thus, when the controller 20 determines that automatic operation of the steering system 46 is necessary to avoid interfering with the operation of the emergency vehicle 14, the controller 20 can cause the steering system 46 to alter the trajectory of the vehicle 10. In the same manner, the feedback unit 28 may be connected to the braking system 50, of the host vehicle 10 to apply the brakes 52 of the host vehicle 10 to avoid interfering with the operation of the emergency vehicle 14. Accordingly, in one embodiment, the mitigation operation includes applying the brakes 52 of the host vehicle 10 and/or altering the trajectory of the host vehicle 10 by manipulating the steering system 46 of the host vehicle 10.
FIGS. 4A and 4B are flow charts illustrating the procedure that the emergency vehicle monitoring system 12 performs in determining whether a mitigation operation is necessary in avoiding interference with the travel path of an emergency vehicle 14. First, the emergency vehicle monitoring system 12 generates host vehicle 10 information in S100. This information can be generated by a navigation unit 22 that is capable of determining location (e.g. latitude and longitude), speed and direction of the host vehicle 10, as described herein. It is noted that the host vehicle 10 information can be generated in any suitable manner, using any suitable system.
Then the receiver 24 of the emergency vehicle monitoring system 12 receives emergency vehicle 14 information with the receiver 24 in S110, the emergency vehicle information can include any suitable information. For example, the emergency vehicle information can include an emergency vehicle 14 emergency status, an emergency vehicle location and an emergency vehicle heading. The emergency status can be whether the emergency vehicle 14 has activated a siren or emergency lights 14a (See FIG. 9-14). Additionally, the emergency status information may simply be a signal that the emergency vehicle 14 is in an emergency status, and engaged in an emergency situation. That is, the emergency vehicle 14 may or may not have a siren and/or lights activated but can be in route to a situation that warrants the emergency vehicle 14 being in emergency status. For example, a police vehicle may be in route to an emergency situation in which lights and sirens are not desired. In such a situation, the emergency vehicle 14 can activate the emergency status signal that is transmitted to and received by the host vehicle 10. The emergency vehicle 14 can be any emergency vehicle 14, such an ambulance, a police car, a fire truck or other emergency vehicle 14.
The controller 20 of the emergency vehicle monitoring system 12 then determines in S120 based on the host vehicle 10 information and the emergency vehicle 14 information, whether the height or elevation of the host vehicle 10 is the same or substantially the same as the emergency vehicle 14. Thus, if the controller 20 determines that the host vehicle 10 and the emergency vehicle 14 are not at the same elevation, the controller 20 can make a determination that the emergency vehicle 14 and the host vehicle 10 are on different road planes. For example, the host vehicle 10 may be on an overpass or underpass, such that the host vehicle 10 will pass over or under the emergency vehicle 14. In such a situation, it would not be necessary for the host vehicle 10 to take any action relative to the emergency vehicle 14. The controller 20 may also compare the elevational difference between the host vehicle 10 and the emergency vehicle 14 and map data and determine that while the vehicles are at different elevations, the vehicles are on a road or roads on which the host vehicle 10 and the emergency vehicle 14 will intersect at a future time due to topography.
The controller 20 in S130 then determines the distance between the host vehicle 10 location and the emergency vehicle 14 location. Preferably, the distance between the host vehicle 10 location and the emergency vehicle 14 location is a straight line distance based on the information provided by the emergency vehicle 14 and generated by the host vehicle 10. The controller 20 determines in S140, based on the host vehicle 10 information and the emergency vehicle 14 information, whether the distance between host vehicle 10 and the emergency vehicle 14 is decreasing. If the distance between the host vehicle 10 and the emergency vehicle 14 is not decreasing, the controller 20 continues to monitor and determine the distance between the host vehicle 10 and the emergency vehicle 14.
In one embodiment, a controller 20 determines a relationship between the host vehicle location and the emergency vehicle location based on a straight line between the host vehicle location and the emergency vehicle location, and an angle between the host vehicle heading and the straight line based on a fixed coordinate system and a preselected angle direction, as discussed in more detail in FIGS. 5-8. In this embodiment, the controller 20 determines whether the host vehicle 10 and the emergency vehicle 14 are travelling on converging paths based on the relationship therebetween. Further, if desired the controller 20 can determine the possibility that the host vehicle 10 and the emergency vehicle 14 will cross paths based on the host vehicle travel time from the host vehicle location to the location at which the host vehicle 10 and the emergency vehicle 14 will cross paths and the travel time from the emergency vehicle location to the location at which the host vehicle 10 and the emergency vehicle 14 will cross paths that is determined based on the emergency vehicle information and determine a threshold value (e.g., a time value and/or distance value) based on a current moving state of the host vehicle 10 while the possibility of the host vehicle 10 and the emergency vehicle 14 cross paths exists. In this embodiment, whether a mitigation operation is necessary can be determined based on the threshold value.
Returning to FIGS. 4A and 4B, when the distance between the host vehicle 10 and the emergency vehicle 14 is decreasing the controller 20 determines the jurisdiction of the location of the host vehicle 10 in S150. This determination can be accomplished based on the host vehicle 10 information generated by the navigation system. For example, the controller 20 can compare the latitude and longitude information of the host vehicle 10 to an electronic map to determine the jurisdiction of the host vehicle 10 (i.e., the city and/or state in which the host vehicle 10 is located). Based on the jurisdiction of the host vehicle 10, the controller 20 determines the emergency vehicle 14 laws that govern the host vehicle 10. The controller 20 can determine the emergency vehicle 14 laws from data stored in the storage device 34 on board the host vehicle 10 or form a storage device (such as remote server or other device) with which the controller 20 is capable of communicating, or in any other suitable manner. That is, once the controller 20 has determined the host vehicle 10 jurisdiction, the emergency vehicle 14 laws can be determined based on a stored table for each jurisdiction in the United States or any other jurisdiction. The emergency vehicle laws may provide information of a distance at which the host vehicle 10 must maintain between the host vehicle 10 and the emergency vehicle 14 and situations in which it may not be necessary to act (e.g., when a median separates the host vehicle 10 and the emergency vehicle 14).
The controller 20 then determines in S160 whether the distance between the host vehicle 10 and the emergency vehicle 14 is less than a first or predetermined threshold distance. When the distance between the host vehicle 10 and the emergency vehicle 14 is less than a threshold distance, the controller 20 causes a mitigation operation to be performed in S170, such as activating a warning. The warning can be any visual, auditory or tactile warning discussed herein. Further, the first threshold distance can be any suitable distance determined based on the emergency vehicle 14 laws for the current jurisdiction, or based on any other suitable determination.
The controller 20 continues to determine the distance between the host vehicle 10 and the emergency vehicle 14 based on host vehicle 10 information and emergency vehicle 14 information in S180, which can be continually updated. When the distance between the host vehicle 10 and the emergency vehicle 14 is not decreasing, the controller 20 determines whether the distance between the host vehicle 10 and the emergency vehicle 14 is less than a second threshold or predetermined distance in S190. The second threshold distance can be the same distance as the first threshold distance or different from the first threshold distance (either less than or greater than). When the distance between the host vehicle 10 and the emergency vehicle 14 is less than the second threshold the controller 20 causes the mitigation operation (e.g., the warning) to be maintained in S170.
When the distance between the host vehicle 10 and the emergency vehicle 14 is not less than the second threshold, the controller 20 causes the mitigation operation (e.g., the warning) to be stopped in S200. That is, when it is determined that the emergency vehicle 14 and the host vehicle 10 are diverging the controller 20 causes the warning to be turned off. This action can be performed at a distance that is less than the first threshold distance, when it is apparent that the emergency vehicle 14 and the host vehicle 10 are travelling in opposite directions and will not converge.
However, when the distance between the host vehicle 10 and the emergency vehicle 14 continues to decrease, the controller 20 determines if the distance is less than or equal to a third threshold or predetermined distance in S210. The third threshold distance is preferably less than the first threshold distance, but can be the same if desired. The third threshold distance can be set based on the emergency vehicle 14 laws for the current jurisdiction. For example, the emergency vehicle 14 laws for the current jurisdiction may require that when following an emergency vehicle 14, the host vehicle 10 is not to be within 500 feet of the emergency vehicle 14. Additionally, the third threshold distance can be set such that the host vehicle may not approach an emergency vehicle 14 within a distance of a standard lane width or some other predetermined distance when passing an emergency vehicle 14 on the road or being passed by an emergency vehicle 14. When the distance between the host vehicle 10 and the emergency vehicle 14 is greater than the third threshold distance, the controller 20 returns to step S190 to determine if the distance between the host vehicle 10 and the emergency vehicle 14 is less than the second threshold distance.
When the distance between the host vehicle 10 and the emergency vehicle 14 is less than the third threshold distance, the controller 20 determines that a mitigation operation (e.g. intervention) should be performed in S220. Under such circumstances, the controller 20 may apply the brakes 52 of the host vehicle 10, or alter the trajectory of the host vehicle 10 by manipulating the steering system 46 of the host vehicle 10.
After the controller 20 begins performance of the mitigation operation, the controller 20 continually determines if the distance between the host vehicle 10 and the emergency vehicle 14 is increasing in S230. When the distance between the host vehicle 10 and the emergency vehicle 14 is decreasing, the controller 20 maintains the mitigation operation in S220. If the distance is increasing, the controller 20 determines whether the distance between the host vehicle 10 and the emergency vehicle 14 is less than a fourth threshold or predetermined distance in S240. If the distance between the host vehicle 10 and the emergency vehicle 14 is less than the fourth threshold distance, the controller 20 maintains the mitigation operation in S220.
However, when the distance is not less than the fourth threshold distance, the controller 20 ceases the mitigation operation in S250, and determines whether the distance is less than the second threshold distance in S190.
It is noted that the steps in the above describe process may be performed in any suitable order and may include additional steps or exclude steps.
Examples of possible locations of an emergency vehicle 14 are shown in the graphs of FIGS. 5 through 8. In these graphs, the heading angle for the host vehicle 10 is represented by δHV and the heading angle for the emergency vehicle 14 is represented by δEV for the emergency vehicle 14 with 0 degrees representing north, π/2 (90 degrees) representing east, π (180 degrees) representing south and 3π/2 (270 degrees) representing west. The sectors are adjacently geographically distributed about the host vehicle 10 location which is at the geographic center of the area where each of the sectors meet. Furthermore, the sectors are separated by a north-south directional line and an east-west directional line that intersect at the host vehicle 10 location. In this case, since there are four sectors, they can be referred to as quadrants.
As shown in FIG. 5, if the emergency vehicle 14 is to the north and east of the host vehicle 10, the emergency vehicle 14 is in the 1st quadrant. If the emergency vehicle 14 is to the north and west of the host vehicle 10, the emergency vehicle 14 is in the 2nd quadrant as shown in FIG. 6. If the emergency vehicle 14 is to the south and west of the host vehicle 10, the emergency vehicle 14 is in the 3rd quadrant as shown in FIG. 7. As shown in FIG. 8, if the emergency vehicle 14 is to the south and east of the host vehicle 10, the emergency vehicle 14 is in the 4th quadrant.
The 1st quadrant is defined by the following conditions:




  
    
      θ
      EV
    
    >
    
      θ
      HV
    
  
  ,
  
    
      φ
      EV
    
    >
    
      φ
      HV
    
  
  ,
  
    
      (
      
        0
        ≤
        
          β
          1
        
        <
        
          π
          2
        
      
      )
    
    .
  




Within the 1st quadrant, certain headings of the host vehicle 10 and the emergency vehicle 14 that result in crossing paths can be determined by the following matrices in Table 1, where δHV<δEV in one matrix and δHV>δEV in the other matrix.







TABLE 1





Matrices Representing Possible Crossing Paths in the 1st Quadrant



















δHV < δEV
YZ
00
01
11





WX

0 ≦ δEV ≦ β1
β1 < δEV ≦ β1 + π
β1 + π < δEV < 2π


00
0 ≦ δHV ≦ β1
0
0
1


01
β1 < δHV ≦ β1 + π
X
1
0


11
β1 + π < δHV < 2π
X
X
0





δHV > δEV
YZ
00
01
11





XW

0 ≦ δEV ≦ β1
β1 < δEV ≦ β1 + π
β1 + π < δEV < 2π


00
0 ≦ δHV ≦ β1
1
X
X


01
β1 < δHV ≦ β1 + π
0
0
X


11
β1 + π < δHV < 2π
0
0
1









These two matrices identify four cases where paths cross (1), eight cases where paths do not cross (0) and six cases that are not possible (x). For example, if the heading angle δHV of the host vehicle 10 is greater than β1 and the heading angle δRV of the emergency vehicle 14 is less than β1, then δHV cannot be less than δEV (WXYZ=0100 for δHV<δEV). It can also be seen that when the emergency vehicle 14 is in the 1st quadrant, the emergency vehicle 14 will be to the left of the host vehicle 10 (EF=01) when the heading angle of the host vehicle 10 is greater than β1 and less than β1+π(β1<δHV<β1+π), otherwise the emergency vehicle 14 will be to the right (EF=11) of the host vehicle 10 (i.e. when β1+π<δHV<β1).
The 2nd quadrant is defined by the following conditions:




  
    
      θ
      EV
    
    <
    
      θ
      HV
    
  
  ,
  
    
      φ
      EV
    
    >
    
      φ
      HV
    
  
  ,
  
    
      (
      
        
          
            3
            2
          
          ⁢
          π
        
        ≤
        
          β
          1
        
        <
        
          2
          ⁢
          π
        
      
      )
    
    .
  




Within the 1st quadrant, certain headings of the host vehicle 10 and the emergency vehicle 14 that result in crossing paths can be determined by the following matrices in Table 2, where δHV<δRV in one matrix and δHV>δRV in the other matrix.







TABLE 2





Matrices Representing Possible Crossing Paths in the 2nd Quadrant



















δHV < δEV
YZ
00
01
11





WX

0 ≦ δEV ≦ β1 − π
β1 − π < δEV ≦ β1
β1 < δEV < 2π


00
0 ≦ δHV ≦ β1 − π
1
0
0


01
β1 − π < δHV ≦ β1
X
0
0


11
β1 < δHV < 2π
X
X
1





δHV > δRV
YZ
00
01
11





WX

0 ≦ δEV ≦ β1 − π
β1 − π < δEV ≦ β1
β1 < δEV < 2π


00
0 ≦ δHV ≦ β1 − π
0
X
X


01
β1 − π < δHV ≦ β1
0
1
X


11
β1 < δHV < 2π
1
0
0









The two matrices identify four cases where paths cross (1), eight cases where paths do not cross (0) and six cases that are not possible (x). For example, if the heading angle δHV of the host vehicle 10 is greater than β1, and the heading angle δEV of the emergency vehicle 14 is less than β1−π, then δHV cannot be less than δRV (WXYZ=1100 for δHV<δEV). It can also be seen that when the emergency vehicle 14 is in the 2nd quadrant, the emergency vehicle 14 will be to the right (EF=11) of the host vehicle 10 when the heading angle of the host vehicle 10 is greater than β1−π and less than β1 (β1−π<δHV<β1) otherwise the emergency vehicle 14 will be to the left (EF=01) of the host vehicle 10 (i.e., when β1<δHV<β1−π).
The 3rd quadrant is defined by the following conditions:




  
    
      θ
      EV
    
    <
    
      θ
      HV
    
  
  ,
  
    
      φ
      EV
    
    <
    
      φ
      HV
    
  
  ,
  
    
      (
      
        π
        ≤
        
          β
          1
        
        <
        
          
            3
            2
          
          ⁢
          π
        
      
      )
    
    .
  




Within the 3rd quadrant, certain headings of the host vehicle 10 and the emergency vehicle 14 that result in crossing paths can be determined by the following matrices in Table 3, where δHV<δEV in one matrix and δHV>δEV in the other matrix.







TABLE 3





Matrices Representing Possible Crossing Paths in the 3rd Quadrant



















δHV < δEV
YZ
00
01
11





WX

0 ≦ δEV ≦ β1 − π
β1 − π < δEV ≦ β1
β1 < δEV < 2π


00
0 ≦ δHV ≦ β1 − π
1
0
0


01
β1 − π < δHV ≦ β1
X
0
0


11
β1 < δHV < 2π
X
X
1





δHV > δRV
YZ
00
01
11





WX

0 ≦ δEV ≦ β1 − π
β1 − π < δEV ≦ β1
β1 < δEV < 2π


00
0 ≦ δHV ≦ β1 − π
0
X
X


01
β1 − π < δHV ≦ β1
0
1
X


11
β1 < δHV < 2π
1
0
0









The two matrices again identify four cases where paths cross (1), eight cases where paths do not cross (0) and six cases that are not possible (x). It should be noted that these matrices are the same as those for the 3rd quadrant. It can also be seen that when the emergency vehicle 14 is in the 3rd quadrant, the emergency vehicle 14 will be to the right (EF=11) of the host vehicle 10 when the heading angle of the host vehicle 10 is greater than β1−π and less than) β1 (β1−π<δHV<β1), otherwise the emergency vehicle 14 will be to the left (EF=01) of the host vehicle 10 (i.e., when β1<δHV<β1−π). This is also the same as if the emergency vehicle 14 were in the 2nd quadrant.
The 4th quadrant is defined by the following conditions:




  
    
      θ
      EV
    
    >
    
      θ
      HV
    
  
  ,
  
    
      φ
      EV
    
    <
    
      φ
      HV
    
  
  ,
  
    
      (
      
        
          π
          2
        
        ≤
        
          β
          1
        
        <
        π
      
      )
    
    .
  




Within the 4th quadrant, certain headings of the host vehicle 10 and the emergency vehicle 14 that result in crossing paths can be determined by the following matrices in Table 4 where δHV<δEV in one matrix and δHV>δEV in the other matrix.







TABLE 4





Matrices Representing Possible Crossing Paths in the 4th Quadrant



















δHV < δEV
YZ
00
01
11





WX

0 ≦ δEV ≦ β1
β1 < δEV ≦ β1 + π
β1 + π < δEV < 2π


00
0 ≦ δHV ≦ β1
0
0
1


01
β1 < δHV ≦ β1 + π
X
1
0


11
β1 + π < δHV < 2π
X
X
0





δHV > δRV
YZ
00
01
11





XW

0 ≦ δEV ≦ β1
β1 < δEV ≦ β1 + π
β1 + π < δEV < 2π


00
0 ≦ δHV ≦ β1
1
X
X


01
β1 < δHV ≦ β1 + π
0
0
X


11
β1 + π < δHV < 2π
0
0
1









The two matrices identify four cases where paths cross (1), eight cases where paths do not cross (0) and six cases that are not possible (x). These matrices are the same as those for the 1st quadrant. It can also be seen that when the emergency vehicle 14 is in the 4th quadrant, the emergency vehicle 14 will be to the left (EF=01) of the host vehicle 10 when the heading angle of the host vehicle 10 is greater than β1 and less than β1+π(β1<δHV<β1+π), otherwise the emergency vehicle 14 will be to the right (EF=11) of the host vehicle 10 (i.e., when β1+π<δHV<β1). This also is the same as if the emergency vehicle 14 were in the 1st quadrant.
Thus, the characteristic relating to the quadrant that includes the emergency vehicle 14 location is different from at least one other characteristic relating to at least one other of the quadrants.
Moreover, as can be appreciated from the above, the processing determines the quadrant in which the emergency vehicle 14 is present by determining a linear direction between the host vehicle 10 and the emergency vehicle 14 at a moment in time, determining an angle between a threshold or predetermined direction and the linear direction at the moment in time, and determining the quadrant in which the emergency vehicle 14 is present based on the angle.
Thus, in these embodiments, the controller 20 is capable of determining whether the emergency vehicle 14 and the host vehicle 10 are on converging paths. Such a determination can facilitate a determination of whether it will be necessary to perform a mitigation operation to enable the emergency vehicle 14 to travel unabated. That is, under the scenarios above, the controller 20 may determine that the host vehicle 10 and the emergency vehicle 14 will cross paths. Under this scenario, the controller 20 may determine that a mitigation operation is necessary. However, the controller 20 may determine that the host vehicle 10 and the emergency vehicle 14 will not cross paths. If this determination is made, and the distance between the host vehicle 10 and the emergency vehicle 14 is greater than a threshold or predetermined distance, a mitigation operation may not be necessary.
FIGS. 9-14 illustrate exemplary scenarios that may require a mitigation operation from the host vehicle 10. FIG. 9 illustrates a scenario in which an emergency vehicle 14 is behind the host vehicle 10 and is traveling at a faster speed than the host vehicle 10. As described above, the host vehicle 10 receives emergency vehicle 14 information, including that the emergency vehicle 14 is in an emergency mode. As the emergency vehicle 14 approaches the host vehicle 10, the controller 20 determines that the distance between the host vehicle 10 and the emergency vehicle 14 is decreasing and the distance is equal to the first threshold or predetermined distance. Moreover, the controller 20 determines that based on the current jurisdiction, the host vehicle 10 must pull over to allow the emergency vehicle 14 to safely pass. The controller 20 performs a mitigation operation by causing the warning indicator 26 to indicate that an emergency vehicle 14 is approaching. For example, the controller 20 may cause a visual warning on the information display unit 44 that reads “Emergency Vehicle Approaching—Pull Over onto the Right Shoulder”, or can be any other suitable warning discussed herein.
As the emergency vehicle 14 approaches, the controller 20 may determine that an additional mitigation operation should be performed. For example, when the distance between the host vehicle 10 and the emergency vehicle 14 is less than the third threshold or predetermined distance, and the host vehicle 10 has not altered its trajectory as required by the current jurisdiction, the controller 20 can apply a mitigation operation, such as applying the brakes of the host vehicle 10 and manipulating the steering system such that the host vehicle 10 pulls over to the right and remains stationary until the emergency vehicle 14 passes.
As the emergency vehicle 14 passes the host vehicle 10, the controller 20 will determine when the emergency vehicle 14 is at a distance from the host vehicle 10 that is greater than the fourth threshold or predetermined distance, terminating the application of brakes and steering manipulation, and when the emergency vehicle 14 is at a distance from the host vehicle 10 that is greater than the second threshold distance, terminate the warning.
FIG. 10 illustrates a scenario in which an emergency vehicle 14 is approaching the host vehicle 10 from the opposite lane on a two lane road. As described above, the host vehicle 10 receives emergency vehicle 14 information, including that the emergency vehicle 14 is in an emergency mode. As the emergency vehicle 14 approaches the host vehicle 10, the controller 20 determines that the distance between the host vehicle 10 and the emergency vehicle 14 is decreasing and the distance is equal to the first threshold distance. Moreover, the controller 20 determines that based on the current jurisdiction, the host vehicle 10 must pull over to allow the emergency vehicle 14 to safely pass. The controller 20 performs a mitigation operation by causing the warning indicator 26 to indicate that an emergency vehicle 14 is approaching. For example, the controller 20 may cause a visual warning on the information display unit that reads “Emergency Vehicle Approaching—Pull Over onto the Right Shoulder”, or can be any other suitable warning discussed herein.
As the emergency vehicle 14 approaches, the controller 20 may determine that an additional mitigation operation should be performed. For example, when the distance between the host vehicle 10 and the emergency vehicle 14 is less than the third threshold distance, and the host vehicle 10 has not altered its trajectory as required by the current jurisdiction, the controller 20 can apply a mitigation operation, such as applying the brakes of the host vehicle 10 and manipulating the steering system such that the host vehicle 10 pulls over to the right and remains stationary until the emergency vehicle 14 passes.
As the emergency vehicle 14 passes the host vehicle 10, the controller 20 will determine when the emergency vehicle 14 is at a distance from the host vehicle 10 that is greater than the fourth threshold distance, terminating the application of brakes and steering manipulation, and when the emergency vehicle 14 is at a distance from the host vehicle 10 that is greater than the second threshold distance, terminate the warning.
FIG. 11 illustrates a scenario in which an emergency vehicle 14 and the host vehicle 10 are approaching an intersection. In this scenario, the emergency vehicle 14 is approaching the intersection from a transverse direction relative to the host vehicle 10, such that if the host vehicle 10 and the emergency vehicle 14 travel unabated they may contact each other or at least cross paths. As described above, the host vehicle 10 receives emergency vehicle 14 information, including that the emergency vehicle 14 is in an emergency mode. As the emergency vehicle 14 approaches the intersection, the controller 20 determines that the distance between the host vehicle 10 and the emergency vehicle 14 is decreasing and the distance is equal to the first threshold distance. Moreover, the controller 20 determines that based on the current jurisdiction, the host vehicle 10 must allow the emergency vehicle 14 to safely pass through the intersection. The controller 20 performs a mitigation operation by causing the warning indicator 26 to indicate that an emergency vehicle 14 is approaching. For example, the controller 20 may cause a visual warning on the information display unit that reads “Emergency Vehicle Approaching—Do Not Enter Intersection”, or can be any other suitable warning discussed herein.
As the emergency vehicle 14 approaches, the controller 20 may determine that an additional mitigation operation should be performed. For example, when the distance between the host vehicle 10 and the emergency vehicle 14 is less than the third threshold distance, and the host vehicle 10 has not altered its trajectory or speed so as to avoid the intersection, the controller 20 can apply a mitigation operation, such as apply the brakes of the host vehicle 10. As the emergency vehicle 14 passes through the intersection, the controller 20 will determine when the emergency vehicle 14 is at a distance from the host vehicle 10 that is greater than the fourth threshold distance, terminating the application of brakes and steering manipulation, and when the emergency vehicle 14 is at a distance from the host vehicle 10 that is greater than the second threshold distance, terminate the warning.
FIG. 12 illustrates a scenario in which an emergency vehicle 14 and the host vehicle 10 are approaching an intersection. In this scenario, the emergency vehicle 14 is approaching the intersection from a direction opposite to the host vehicle 10. In this scenario, the host vehicle 10 information includes information that the host vehicle 10 is intending to turn at the intersection, such that if the host vehicle 10 and the emergency vehicle 14 travel unabated they may contact each other or at least cross paths. As described above, the host vehicle 10 receives emergency vehicle 14 information, including that the emergency vehicle 14 is in an emergency mode. As the emergency vehicle 14 approaches the intersection, the controller 20 determines that the distance between the host vehicle 10 and the emergency vehicle 14 is decreasing and the distance is equal to the first threshold distance. Moreover, the controller 20 determines that based on the current jurisdiction, the host vehicle 10 must allow the emergency vehicle 14 to safely pass through the intersection. The controller 20 performs a mitigation operation by causing the warning indicator 26 to indicate that an emergency vehicle 14 is approaching. For example, the controller 20 may cause a visual warning on the information display unit that reads “Emergency Vehicle Approaching—Do Not Enter Intersection”, or can be any other suitable warning discussed herein.
As the emergency vehicle 14 approaches, the controller 20 may determine that an additional mitigation operation should be performed. For example, when the distance between the host vehicle 10 and the emergency vehicle 14 is less than the third threshold distance, and the host vehicle 10 has not altered its trajectory or speed so as to avoid the intersection, the controller 20 can apply a mitigation operation, such as apply the brakes of the host vehicle 10.
As the emergency vehicle 14 passes through the intersection, the controller 20 will determine when the emergency vehicle 14 is at a distance from the host vehicle 10 that is greater than the fourth threshold distance, terminating the application of brakes and steering manipulation, and when the emergency vehicle 14 is at a distance from the host vehicle 10 that is greater than the second threshold distance, terminate the warning.
FIG. 13 illustrates a scenario in which an emergency vehicle 14 and the host vehicle 10 are approaching an intersection. In this scenario, the emergency vehicle 14 is approaching the intersection from a direction opposite to the host vehicle 10. In this scenario, the emergency vehicle 14 information includes information that the emergency vehicle 14 is intending to turn at the intersection, such that if the host vehicle 10 and the emergency vehicle 14 travel unabated they may contact each other or at least cross paths. As described above, the host vehicle 10 receives emergency vehicle 14 information, including that the emergency vehicle 14 is in an emergency mode. As the emergency vehicle 14 approaches the intersection, the controller 20 determines that the distance between the host vehicle 10 and the emergency vehicle 14 is decreasing and the distance is equal to the first threshold distance. Moreover, the controller 20 determines that based on the current jurisdiction, the host vehicle 10 must allow the emergency vehicle 14 to safely pass through the intersection. The controller 20 performs a mitigation operation by causing the warning indicator 26 to indicate that an emergency vehicle 14 is approaching. For example, the controller 20 may cause a visual warning on the information display unit that reads “Emergency Vehicle Approaching—Do Not Enter Intersection”, or can be any other suitable warning discussed herein.
As the emergency vehicle 14 approaches, the controller 20 may determine that an additional mitigation operation should be performed. For example, when the distance between the host vehicle 10 and the emergency vehicle 14 is less than the third threshold distance, and the host vehicle 10 has not altered its trajectory or speed so as to avoid the intersection, the controller 20 can apply a mitigation operation, such as apply the brakes of the host vehicle 10.
As the emergency vehicle 14 passes through the intersection, the controller 20 will determine when the emergency vehicle 14 is at a distance from the host vehicle 10 that is greater than the fourth threshold distance, terminating the application of brakes and steering manipulation, and when the emergency vehicle 14 is at a distance from the host vehicle 10 that is greater than the second threshold distance, terminate the warning.
FIG. 14 illustrates a scenario in which an emergency vehicle 14 is approaching the host vehicle 10 from the opposite lane on a multilane road with a median therebetween. As described above, the host vehicle 10 receives emergency vehicle 14 information, including that the emergency vehicle 14 is in an emergency mode. As the emergency vehicle 14 approaches the host vehicle 10, the controller 20 determines that the distance between the host vehicle 10 and the emergency vehicle 14 is decreasing. However, since the emergency vehicle 14 and the host vehicle 10 are separated by multiple lanes and a median, the distance between the host vehicle 10 and the emergency vehicle 14 is not less than the first threshold distance. Thus, the controller 20 does not perform a mitigation operation.
Alternatively, the controller 20 may determine that based on the current jurisdiction that it is not necessary to perform any action when an emergency vehicle 14 is traveling in the opposite direction from the host vehicle 10 on a road that includes a median.
In another embodiment, the emergency vehicle 14 can be stopped on the side of the road. For example, a police car or an ambulance can be on the shoulder of a road attending to a person on the shoulder of the road. In such a scenario, the jurisdictional laws may require the host vehicle 10 to slow down or move to a lane away from the emergency vehicle. In this scenario, the lane width or the lateral distance between the host vehicle and the emergency vehicle can be the threshold distance.
The above scenarios are merely exemplary and numerous additional intersection and road scenarios are possible.
The emergency vehicle monitoring system 12 and method described herein provides emergency vehicle 14 information to host vehicle 10 so as to improve vehicle safety and abide by local jurisdictional requirements in enabling emergency vehicles 14 to travel unabated.
Moreover, when the emergency vehicle 14 is not in an emergency situation, and thus the emergency vehicle 14 is not in an emergency mode, the host vehicle 10 may treat the emergency vehicle 14 as a remote vehicle. For example, see U.S. patent application Ser. No. 13/952,414, entitled “Vehicle Collision Monitoring Method”, U.S. patent application Ser. No. 13/689,523, entitled “Vehicle Intersection Monitoring System and Method”, U.S. patent application Ser. No. 13/689,452, entitled “Vehicle Intersection Monitoring System and Method”, U.S. patent application Ser. No. 13/689,484, entitled “Vehicle Intersection Monitoring System and Method”, and U.S. patent application Ser. No. 13/689,564, entitled “Vehicle Intersection Monitoring System and Method”, all of these applications being incorporated by reference herein, which discuss the treatment of remote vehicles.
The storage devices and GPS 32 are conventional components that are well known in the art. Since storage devices and GPS 32 are well known in the art, these structures will not be discussed or illustrated in detail herein. Rather, it will be apparent to those skilled in the art from this disclosure that the components can be any type of structure and/or programming that can be used to carry out the present invention.
In understanding the scope of the present invention, the term “comprising” and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and/or steps. The foregoing also applies to words having similar meanings such as the terms, “including”, “having” and their derivatives. Also, the terms “part,” “section,” or “portion” when used in the singular can have the dual meaning of a single part or a plurality of parts. Also as used herein to describe the above embodiment(s), the following directional terms “front”, “rear”, “left”, and “right” as well as any other similar directional terms refer to those directions of a vehicle equipped with the Method and System of Assisting a Driver of a Vehicle. Accordingly, these terms, as utilized to describe the present invention should be interpreted relative to a vehicle equipped with the Method and System of Assisting a Driver of a Vehicle.
The term “detect” as used herein to describe an operation or function carried out by a component, a section, a device or the like includes a component, a section, a device or the like that does not require physical detection, but rather includes determining, measuring, modeling, predicting or computing or the like to carry out the operation or function.
The term “configured” as used herein to describe a component, section or part of a device includes hardware and/or software that is constructed and/or programmed to carry out the desired function.
While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. For example, the size, shape, location or orientation of the various components can be changed as needed and/or desired. Components that are shown directly connected or contacting each other can have intermediate structures disposed between them. The functions of one element can be performed by two, and vice versa. The structures and functions of one embodiment can be adopted in another embodiment. It is not necessary for all advantages to be present in a particular embodiment at the same time. Every feature which is unique from the prior art, alone or in combination with other features, also should be considered a separate description of further inventions by the applicant, including the structural and/or functional concepts embodied by such feature(s). Thus, the foregoing descriptions of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

## Claims

1. A method of monitoring an emergency vehicle, comprising: generating host vehicle information with a navigation unit, the host vehicle information including a host vehicle location and a host vehicle heading;
receiving emergency vehicle information with a receiver, the emergency vehicle information including an indication of a positive emergency vehicle emergency status, an emergency vehicle location and an emergency vehicle heading;
determining with a controller a direct distance between the host vehicle location and the emergency vehicle location;
determining with the controller whether the direct distance between host vehicle and the emergency vehicle is decreasing;
performing a mitigation operation, when the indication of the positive emergency vehicle emergency status is received, and when the direct distance between host vehicle and the emergency vehicle is decreasing, the direct distance between host vehicle and the emergency vehicle is a first threshold distance or less, and when no threat of contact exists between the host vehicle and the emergency vehicle;
ceasing the mitigation operation when the direct distance between the host vehicle and the emergency vehicle is greater than a second threshold distance; and
classifying the emergency vehicle as a remote vehicle when the indication of the positive emergency vehicle emergency status is inactive.

2. The method according to claim 1, wherein
the threshold distance is a first threshold distance, and ceasing the mitigation operation when the direct distance between the host vehicle and the emergency vehicle is greater than a second threshold distance.

3. The method according to claim 2, wherein
the second threshold is less than the first threshold.

4. The method according to claim 2, wherein
the second threshold is equal to the first threshold.

5. The method according to claim 2, further comprising
performing an intervention operation when the direct distance between host vehicle and the emergency vehicle is decreasing, and the direct distance between the host vehicle and the emergency vehicle is a third threshold distance or less.

6. The method according to claim 5, wherein
the third threshold distance is less than the first threshold distance.

7. The method according to claim 6, further comprising
ceasing the intervention operation when the direct distance between the host vehicle and the emergency vehicle is greater than a fourth threshold distance.

8. The method according to claim 7, wherein
fourth threshold distance is less than the second threshold distance.

9. The method according to claim 5, wherein
the performing the intervention operation includes at least one of braking the host vehicle and altering the trajectory of the host vehicle.

10. The method according to claim 5, wherein
the performing the intervention operation includes maintaining at least the third threshold distance between the host vehicle and the emergency vehicle.

11. The method according to claim 10, further comprising
determining with the controller jurisdictional rules with respect to emergency vehicles at the host vehicle location.

12. The method according to claim 11, wherein
determining with the controller the jurisdictional rules includes determining the jurisdictional distance to be maintained between the host vehicle and the emergency vehicle.

13. The method according to claim 12, wherein
the performing the intervention operation includes operating brakes of the host vehicle to maintain the third threshold distance.

14. The method according to claim 12, wherein
the performing the intervention operation includes altering the trajectory of the host vehicle to maintain the third threshold distance.

15. The method according to claim 1, further comprising
determining with the controller jurisdictional rules with respect to emergency vehicles at the host vehicle location.

16. The method according to claim 15, wherein
the performing the mitigation operation includes at least one of notifying occupants of the host vehicle of the jurisdictional rules and notifying the occupants of the host vehicle of a jurisdictional distance to maintain from the emergency vehicle.

17. The method according to claim 1, wherein
the activating the advisory includes at least one of activating an interior warning light and activating an auditory advisory.

18. The method according to claim 1, wherein
the receiving emergency vehicle information with a receiver includes receiving vehicle information from at least one of an ambulance, a police car, and a fire truck, indicating that the at least one of the ambulance, the police car, and the fire truck has at least one of a siren and an emergency light activated.

19. The method according to claim 1, further comprising
performing a second mitigation operation, when the indication of the positive emergency vehicle emergency status is inactive, when the direct distance between host vehicle and the emergency vehicle is decreasing, and when the direct distance between host vehicle and the emergency vehicle is a second threshold distance or less.

20. The method according to claim 1, further comprising
receiving remote vehicle information with the receiver, the remote vehicle information including, a remote vehicle location and a remote vehicle heading, and
classifying the emergency vehicle as a remote vehicle when the indication of the positive emergency vehicle emergency status is inactive.