Patent Publication Number: US-2018039268-A1

Title: Automated vehicle operator skill evaluation system

Description:
TECHNICAL FIELD OF INVENTION 
     This disclosure generally relates to an operator-evaluation system for an automated vehicle, and more particularly relates to a system that determines a skill-ranking of an operator and compares the skill-ranking to a complexity-ranking of an upcoming traffic-scenario to determine if the operator is capable of operating the vehicle in a manual-mode. 
     BACKGROUND OF INVENTION 
     It is expected that in certain situations or traffic-scenarios it will be necessary for an automated-vehicle to relinquish control of the vehicle to a human-operator such as an occupant or a remote-operator of the automated-vehicle. For example, it may be that map-data is relatively sparse for an upcoming section of a selected travel-route, so it may be seem to be safer to have the human-operator take control of the vehicle. However, if the occupant is for some reason unable to assume control, e.g. the operator is ill, incapacitated, intoxicated, or the remote control link is severed, alternative actions by the controller within the automated vehicle may be necessary. 
     SUMMARY OF THE INVENTION 
     In accordance with one embodiment, an operator-evaluation system for an automated vehicle is provided. The system includes a traffic-detector and a controller. The traffic-detector is used to determine a complexity-ranking of a traffic-scenario approached by a host-vehicle. The controller is in communication with the traffic-detector. The controller is configured to operate the host-vehicle in: an automated-mode wherein the controller steers the host-vehicle toward a desired-position of a travel-lane; a monitored-mode wherein an operator steers the host-vehicle and the controller assists the operator to steer the host-vehicle toward the desired-position when the host-vehicle is farther than a lateral-threshold from the desired-position; and a manual-mode wherein the operator steers the host-vehicle without assistance from the controller when the controller is unable to navigate the traffic-scenario. The controller transitions from the automated-mode to the monitored-mode prior to arrival at the traffic-scenario to determine a skill-ranking of the operator relative to the complexity-ranking, and transitions from the automated-mode to the manual-mode when the complexity-ranking is not greater than the skill-ranking of the operator. 
     Further features and advantages will appear more clearly on a reading of the following detailed description of the preferred embodiment, which is given by way of non-limiting example only and with reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The present invention will now be described, by way of example with reference to the accompanying drawings, in which: 
         FIG. 1  is a diagram of an operator-evaluation system in accordance with one embodiment; 
         FIG. 2  is an illustration of a roadway encountered by the system of  FIG. 1  in accordance with one embodiment. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  illustrates a non-limiting example of an operator-evaluation system, hereafter referred to as the system  10 , which is generally intended for use by an automated vehicle, for example the host-vehicle  12 . As will be explained in more detail below, the system  10  described herein is an improvement over prior systems capable of both fully automated and manual (human driven) operation because the system  10  tests or evaluates the ability of an operator  14  to take manual control of the host-vehicle  12  prior to the system  10  actually relinquishing automated control of the host-vehicle  12 . For example, when the system  10  deems an upcoming situation or traffic-scenario to be too complicated or otherwise unsuitable for fully automated or autonomous control of the host-vehicle  12 , the system  10  seeks to identify some way to test the ability of the operator  14  to safely operate the host-vehicle  12  prior to actually relinquishing control. For example, if the operator  14  is a passenger in the host-vehicle  12 , it may be that the operator  14  is ill, injured, intoxicated, or otherwise incapacitated at least with regard to operating a motor vehicle. It is also contemplated that the teachings presented herein are applicable to an automated vehicle that generally operates autonomously, but is controlled by a remote-operator (rather than a passenger if the host-vehicle is used to transport passengers) if necessary. For example, the communications link between the host-vehicle  12  and the remote-operator may not be operating due to an equipment failure, or because the communications link is being maliciously jammed or otherwise interfered with, i.e. hacked. 
     The system  10  includes a traffic-detector  16  used to detect one or more instances of an other-vehicle  18  proximate to the host-vehicle  12 , and/or features of a roadway  34  traveled by the host-vehicle  12 . The traffic-detector may include any one or more of a camera  20 , a radar-unit  22 , a lidar-unit  24 , an ultrasonic transducer  26 , or any combination thereof. The traffic-detector  16  may also include a global-position-system-receiver, hereafter the GPS receiver  28 , which is used to determine a location of the host-vehicle  12  on a digital-map  30 . The traffic-detector  16  may also include a transceiver  32  that is used for, but not limited to, vehicle-to-infrastructure (V2I) communications, vehicle-to-vehicle (V2V) communications, and/or vehicle-to-pedestrian (V2P) communications, which may be generically labeled as V2X communications  36 . V2X communications may be used to determine the location on the digital-map  30  and detect the other-vehicle  18 , as will be recognized by those in the art. 
     The system  10  includes a controller  40  in communication with the traffic-detector  16 . The controller  40  may include a processor (not specifically shown) such as a microprocessor or other control circuitry such as analog and/or digital control circuitry including an application specific integrated circuit (ASIC) for processing data as should be evident to those in the art. The controller  40  may include memory (not specifically shown), including non-volatile memory, such as electrically erasable programmable read-only memory (EEPROM) for storing one or more routines, thresholds, and captured data. The one or more routines may be executed by the processor to perform steps for operating the host-vehicle  12  based on signals received by the controller  40  from the traffic-detector  16  as described herein. 
     The traffic-detector  16  is used by the controller  40  to determine a complexity-ranking  42  of a traffic-scenario  44  approached by the host-vehicle  12 . As used herein, the traffic-scenario  44  is used to identify an upcoming section or area of the roadway  34  that may require more action by the controller  40  and/or the operator  14  than is necessary when the host-vehicle  12  is traveling a straight road without any complications such as possible interference by other vehicles or obstacles, or a traffic-signal/stop-sign. By way of example and not limitation, examples of the traffic-scenario  44  include an exit  46  ( FIG. 2 ) from the roadway  34  onto a side-road  48 , an intersection  50 , a traffic-circle (not shown), or a stopped-vehicle (not shown) on the roadway  34 . The complexity-ranking  42  may be, for example, a numerical value ranging from one (1) to five (5), which is used to quantify how complicated will be the navigation of the traffic-scenario  44 . For example, if the roadway  34  is relatively straight, the lane-markings  52  of the roadway  34  are easily detected by the traffic-detector  16 , and the roadway  34  is clear of debris and dry, a suitable value for the complexity-ranking  42  is one (1). However, if there is a multi-vehicle accident (not shown) detected ahead of the host-vehicle  12 , and emergency-vehicles are present on-site, and a police-officer directing traffic around the site of the accident, a suitable value for the complexity-ranking  42  is five (5). It is contemplated that the V2X communications  36  may inform the controller  40  of such an accident before it can be detected by, for example, the camera  20 . 
     Examples of other factors that can increase the value of the complexity-ranking  42  of the traffic-scenario  44  include instances where the roadway  34  or side-road  48  are characterized as having inadequate map-data, i.e. information on the digital-map  30  at the location of the traffic-scenario  44  is relatively sparse or out-of-date. Other examples are instance of freeway transitions where the quality/consistency of the lane-markings  52  may suddenly change, small radius exit loops that require precise steering and speed control of the host-vehicle  12 , traffic-circles where predicting the travel-path of the other-vehicle  18  may be difficult, a stopped-vehicle ahead of the host-vehicle  12  where the future actions of the stopped-vehicle are unknown, traffic flow patterns that require a merge or lane-change, speed limit changes, etc. 
     The controller  40  is configured to operate the host-vehicle  12  in an automated-mode  54  where the controller  40 , for example, steers the host-vehicle  12  toward a desired-position  56  of a travel-lane  58  using the vehicle-controls  60 . The desired-position  56  may be, but is not required to be, the center of the travel-lane  58 . It is contemplated that the automated-mode  54  also controls the speed of the host-vehicle  12  by operating the accelerator and brakes in addition to operating the steering. While operating in the automated-mode  54  a passenger of the host-vehicle  12 , e.g. the operator  14  if the operator is on-board the host-vehicle  12 , does little more than possibly designate a destination. That is, while in the automated-mode the operator  14  will typically not operate or influence the vehicle-controls  60  unless the operator  14  detects a danger and, for example, physically overrides the operation of the steering and/or brakes. 
     The controller  40  is also configured to operate the host-vehicle  12  in a manual-mode  62  where the operator  14  at least steers the host-vehicle  12 . While operating in the manual-mode  62 , operation of the host-vehicle is generally the sole responsibility of the operator, so is generally done without assistance from the controller  40 . However, it is contemplated that the operator  14  may activate a speed-control system (i.e. cruise-control) while remaining in the manual-mode  62 . It is also contemplated that some safety systems would still be active such as automatic-braking that engages to prevent a collision, or dynamic vehicle control that assists the operator  14  to recover from a skid. A general characteristic of the safety systems that would still be active while operating in the manual-mode  62  is that the operator  14  would not detect that those safety-systems were active unless the safety-system acted in some way to assist the operator  14  in an emergency situation. 
     It is envisioned that safety systems like a lane-keeping-system would be deactivated to prevent undue interference with control of the host-vehicle  12  by the operator  14 . In particular, the operator  14  would be able to drive on a shoulder (not shown) of the roadway  34  without interference by the lane-keeping-system. The general purpose of the manual-mode  62  is to provide the option to the operator  14  to drive the host-vehicle  12  because the operator  14  may enjoy driving, and/or provide for a means to operate the host-vehicle when the controller  40  is unable to navigate or operate the host-vehicle  12  though the traffic-scenario  44 . For example, if it is necessary to momentarily steer the host-vehicle  12  off of the roadway  34  to navigate around the aforementioned multi-vehicle accident, it may be prudent to have the operator  14  control the host-vehicle  12  rather than rely on the controller  40  to control the host-vehicle in such a rather complex and unpredictable example of the traffic-scenario  44 . 
     The controller  40  is also configured to operate the host-vehicle  12  in a monitored-mode  64  where, for example, the operator  14  steers the host-vehicle  12  and the controller  40  assists the operator  14  to steer the host-vehicle  12  toward the desired-position  56  when the host-vehicle  12  is farther than a lateral-threshold  66  from the desired-position  56 . That is, while operating in the monitored-mode  64 , the operation of the host-vehicle  12  would seem to the operator  14  to be the same as or equivalent to the manual-mode  62 , unless the operator allowed the host-vehicle  12  to deviate too far from the desired-position  56 , more than one-point-five meters (1.5 m) for example. By way of another non-limiting example, if while operating in the monitored-mode  64  the operator  14  becomes too close to another vehicle (not shown) forward of the host-vehicle  12 , i.e. the operator  14  is tail-gating another vehicle, the controller  40  may momentarily override the operation of the accelerator and/or the brakes to establish a safer following distance for the host-vehicle  12 . 
     It has been determined by researchers and engineers working to develop automated vehicles that there is often substantial uncertainty when a transition from the automated-mode  54  to the manual-mode  62  is executed because the mental and physical state of the operator  14  is uncertain. For example, while operating in the automated-mode the operator  14  may have fallen asleep or become ill, or the operator  14  may have initiated the automated-mode  54  because the operator  14  was ill and needed to be taken to a hospital. Various schemes have been suggested to provide advanced warnings to the operator  14  and/or execute an early transition from the automated-mode to the manual-mode while the complexity-ranking  42  is low at a location well in advance of the complexity-ranking of the traffic-scenario  44  is too great for the automated-mode  54 . However, the schemes do not address the fundamental problem of not knowing the state, capability, or capacity of the operator  14  to assume control of the host-vehicle, hereafter referred to as the skill-ranking  68  of the operator  14 . 
     In order to determine the skill-ranking  68 , the controller  40  transitions from the automated-mode  54  to the monitored-mode  64  prior to arrival at the traffic-scenario  44  that requires the manual-mode  62 . This transition may be initiated by a visual and/or audible indication detectable by the operator  14  that the manual-mode  62  (unbeknownst to the operator  14  that it is actually the monitored-mode  64 ) is being engaged. Alternatively, the indication may inform the operator  14  the monitored-mode  64  is being engaged to verify that the operator  14  is able to take control. The skill-ranking  68  of the operator  14  is determined relative to the complexity-ranking  42  by measuring how well the operator  14  negotiates a prior instance of the traffic-scenario  44  selected to determine the skill-ranking  68  prior to arriving at a subsequent instance of the traffic-scenario  44  that requires the operator  14  to be in control of the host-vehicle  12 . As suggested above, safety systems such as lane-keeping and automated-braking may still be activated while in the monitored-mode  64 , but the thresholds for engagement of these systems may be changed to allow for more error on the part of the operator  14  while being monitored to determine the skill-ranking  68 . 
     Once the skill-ranking  68  is determined, i.e. a most recent or a present-ranking  70  of the operator  14  is recorded, the controller  40  may confidently transition from the automated-mode  54  to the manual-mode  62  if/when the complexity-ranking  42  of the upcoming instance of the traffic-scenario is not greater than the most recent value of the skill-ranking  68  (i.e. the present-ranking  70 ) of the operator  14 . It is preferable that the skill-ranking  68  be determine as close to the traffic-scenario  44  that requires the manual-mode  62  so the operator  14  does not fall asleep during the interim. 
       FIG. 2  illustrate a non-limiting example of the roadway  34  traveled by the host-vehicle  12  where a second-scenario  44 B requires the manual-mode  62  because the digital-map  30  ( FIG. 1 ) does not contain sufficient information for the automated-mode  54  to be used to operate the host-vehicle  12  on the side-road  48 . The roadway  34  includes some curves identified as a first-scenario  44 A that may be used to determine the skill-ranking  68  of the operator  14 . By way of further example, because the digital-map  30  does not contain sufficient information for the automated-mode  54  to be used to navigate the second-scenario  44 B, but there are no indications of accidents or other impediments to travel on the side-road  48 , the complexity-ranking  42  may be set at four (4). By comparison, the multi-vehicle accident described above that may require the host-vehicle  12  to travel off the roadway  34  to circumnavigate may have the complexity-ranking  42  set at five (5). By further comparison, the first-scenario  44 A includes some curves so the first-scenario  44 A would be assigned a greater value for the complexity-ranking  42 , two (2) for example. The complexity-ranking  42  of traffic-scenarios may be stored in the digital-map  30 , or may be calculated by the controller  40  drawing upon information from the digital-map  30  and/or the various sensors that form the traffic-detector  16 . 
     In anticipation of arriving at the second-scenario  44 B, the controller  40  engages the monitored-mode  64  prior to arriving at the first-scenario  44 A. If the operator  14  navigates the first-scenario  44 A well, so the is no indication that the operator  14  is nothing less than fully capable of operating the host-vehicle  12  in the manual-mode  62 , then the skill-ranking  68  is set to five (5), the highest value for the skill-ranking  68  in this example because the range of values corresponds to the range of values used for the complexity-ranking  42 . However, if the operator  14  allows the host-vehicle  12  deviate or drift too far from the desired-position  56 , e.g. the center of the travel-lane  58 , the skill-ranking is lowered based on how far from the desired-position  56  the operator allows the host-vehicle  12  to drift. 
     For example, if the drift is more than one meter (1 m), but the tires of the host-vehicle  12  do not touch the lane-markings  52 , the skill-ranking  68  may be set to four (4). Similarly, if the tires cross the lane-markings  52 , but do not go off the roadway  34  onto a shoulder for example, then the skill-ranking  68  may be set to three (3). Excessive amounts of steering correction (i.e. weaving) and or speed variation may also cause the skill-ranking  68  to be lowered. It is noted that even though the first-scenario  44 A in this example has a value for the complexity-ranking less than five (5), the skill-ranking  68  can be set to a value equal to five (5) by measuring the driving behavior of the operator  14 . It is again noted that during the monitored-mode  64  the controller  40  may intervene with operation of the host-vehicle  12  if the operator  14  is unable to adequately control the host-vehicle  12 . That is, the system  10 , or more specifically the controller  40  may transaction back to the automated-mode  54  and take control of the host-vehicle  12  from the operator  14 . 
     In the event that the complexity-ranking  42  of the second-scenario  44 B is greater than the skill-ranking  68  of the operator  14 , and the complexity-ranking  42  of the traffic-scenario  44  (e.g. the second-scenario  44 B) is greater than some value of a confidence-ranking  72  (e.g. 3, the determination of which will be describe in more detail later.), which would prevent operating in the automated-mode  54 , the controller  40  may bypass the traffic-scenario  44  (e.g. drive past the exit  46  to bypass the second-scenario  44 B) and seek an alternative route to the destination that does not include a traffic-scenario with a complexity-ranking greater than the confidence-ranking  72 . That is, the controller  40  operates the host-vehicle  12  in the automated-mode  54  to bypass the traffic-scenario  44  (e.g. stays on the expressway or main road instead of taking the exit  46 ) when the complexity-ranking  42  of the traffic-scenario  44  is greater than the skill-ranking  68  of the operator  14 . While the examples presented so far suggest that the complexity-ranking  42  and the skill-ranking  68  are integer values, it is contemplated that fractional values will be useful, e.g. three-point three (3.3). 
     An interpretation of the description above may suggest to some that the skill-ranking  68  is not saved for future use. However, this is not the case as it is further contemplated that the controller  40  may be configured to operate the host-vehicle  12  in the monitored-mode  64  to update the skill-ranking  68  when a present-ranking  70  of the operator  14  is less than the complexity-ranking  42  of the traffic-scenario  44  approached by the host-vehicle  12 . That is, it is contemplated that the skill-ranking  68  was previous determined to be rather low because, for example, the operator  14  was momentarily distracted or there was some good reason for the operator  14  to swerve that went undetected by the system  10 . Accordingly, the controller  40  may periodically and repeatedly engage the monitored-mode  64  to confirm that the skill-ranking  68  was properly set if the present-ranking  70  from a prior instance of operating in the monitored-mode caused the skill-ranking  68  to be low. By way of further example of how the present-ranking  70  may be updated  74 , the controller  40  may increase the skill-ranking  68 , which is subsequently stored as the present-ranking  70 , when operator  14  steers the host-vehicle  12  to less than the lateral-threshold  66  from the desired-position  56 , and decrease the skill-ranking  68  when operator  14  steers the host-vehicle to not less than the lateral-threshold  66  from the desired-position  56 . 
     It is contemplated that there are other ways to measure or determine the skill-ranking  68  of the operator  14 . For example, the controller  40  may use information from the radar-unit  22  or other suitable ranging device to determine the following distance of the host-vehicle  12  behind a forward-vehicle (not shown) traveling in front of the host-vehicle  12 . If the operator  14  follows the forward-vehicle too closely, i.e. tail-gates the forward-vehicle, the skill-ranking  68  may be reduced. Similarly, if the operator  14  does not keep-up with the forward-vehicle, this may cause an undesirable inefficiency for traffic as a whole because the operator  14  is traveling too slowly, so for this the skill-ranking  68  may also be reduced. This assumes that the forward-vehicle is traveling at a safe speed. If the operator  14  follows the forward-vehicle at an appropriate distance, the skill-ranking  68  may be increased. While operating in the monitored-mode  64  the system  10  may issue an audible and/or visible warning to the operator  12  if tail-gating is detected, and may apply the brakes if the host-vehicle  12  is close to contacting the forward-vehicle. 
     As another example of other ways to measure or determine the skill-ranking  68  of the operator  14 , excessive/unnecessary variation in speed may cause an undesirable inefficiency for traffic as a whole, so the skill-ranking  68  may be reduced. Steady speed control helps to save fuel in the host-vehicle  12  and in following-vehicles (not shown) following the host-vehicle  12 . Indeed, it is contemplated that if the operator  14  is able to travel at a steady speed by allowing for speed variations by the forward-vehicle, the skill-ranking  68  may be increased. 
     By way of further example and not limitation, the complexity-ranking  42  may be further determined based on a traffic-density  76  indicative of how many other vehicles are proximate to, e.g. within one-hundred meters (100 m) of, the host-vehicle  12 , where the complexity-ranking is increased if the traffic-density  76  is greater that a density-threshold, fifteen (15) instances of other vehicles within 100 m. The complexity-ranking  42  may be further determined based on a traffic-speed  78 , e.g. an average speed of the other vehicles proximate to the host-vehicle  12 , where higher speeds and other-vehicles exceeding the speed-limit will increase the complexity-ranking  42 . The complexity-ranking  42  may be further determined based on a weather-condition  80  where a dry road-surface may have no effect on the complexity-ranking  42 , a wet road-surface may increase the complexity ranking by a small amount (e.g. less than 1) and an ice covered road-surface my increase the complexity-rank by a larger amount (e.g. greater than 1). The complexity-ranking  42  may be further determined based on a lane-maneuver  82  where the value may be increased if the traffic-scenario  44  includes a lane-change or lane-shift, and the value may be unchanged if no lane-change is expected. The complexity-ranking  42  may be further determined based on a speed-change  84  where acceleration/deceleration may increase the complexity-ranking  42 , and constant-speed through the traffic-scenario  44  may not change the complexity-ranking  42 . The complexity-ranking  42  may be further determined based on a road-type  86  where a curved, crowned, and/or banked road may increase the complexity-ranking  42 , and a straight and or flat road may not change the complexity-ranking  42 . 
     As suggested above, the controller  40  allows operation of the host-vehicle  12  to transition from the manual-mode  62  to the automated-mode  54  when the complexity-ranking  72  of the traffic-scenario  44  is not greater than the confidence-ranking  72  of the controller  40 . The confidence-ranking  72  may be determined based on, but not limited to, one or more of: a lane-marking-quality  88  indicative of how readily and consistently the lane-markings  52  are detected by, for example, the camera  20 ; an object-tracking-persistence  90  indicative of how time and/or repeatedly detected in is an object, e.g. the other-vehicle  18 ; and a global-position-accuracy  92  indicative of how well does the GPS coordinates determined using the GPS receiver  28  correspond to a relative position of the lane-markings  52 . 
     Accordingly, an operator-evaluation system (the system  10 ), a controller  40  for the system  10 , and a method of operating the system  10  is provided. The system  10  overcomes some of the uncertainty arising from a transition from the automated-mode  54  to the manual-mode  62  because the skill-ranking of the operator  14  is determined prior to the transition. The skill-ranking  68  is determined during the monitored-mode  64  where the operator  14  is given limited control, and the controller  40  is ready to take back control if the operator  14  is not capable. The monitored-mode  64  is initiated prior to arriving at a traffic-scenario  44  where a complexity-ranking  42  of the traffic-scenario  44  indicates that the traffic-scenario  44  is too complicated for the automated-mode  54 . 
     While this invention has been described in terms of the preferred embodiments thereof, it is not intended to be so limited, but rather only to the extent set forth in the claims that follow.