Fail-safe speed profiles for cooperative autonomous vehicles

1. Method for controlling speed of a vehicle based upon control messages received through a communications device within the vehicle, the method comprising:

monitoring communication of control messages from an autonomous controller within the vehicle through the communications device within the vehicle to a propulsion controller within the vehicle wherein control messages comprise a speed profile including a current speed command representing instantaneous desired speed of the vehicle and future speed commands representing a predetermined controlled vehicle stop through a speed profile period;

detecting anomalous communications of the control messages through the communications device, the anomalous communications detected by determining one of

irregular control message arrival times from the autonomous controller to the propulsion controller, and

mismatched counter measurements between consecutive control messages sent by the autonomous controller to the propulsion controller; and

controlling the speed of the vehicle during anomalous communications using the speed profile, comprising

determining the speed profile period containing a distance confirmed to be clear to traverse by the vehicle at the time the anomalous conditions are detected, and

controlling the speed of the vehicle according to the current speed command at the time the anomalous conditions are detected until the vehicle has traversed a predetermined percentage of the speed profile period, and subsequently, reducing the speed of the vehicle according to the future speed commands.

2. The method of claim 1 , further comprising:

detecting restoration of communications from detected anomalous communications including receiving an updated speed profile at the propulsion controller including an updated current speed command and updated future speed commands; and

controlling the speed of the vehicle when communications are restored from detected anomalous communications using the updated speed profile.

3. The method of claim 2 , wherein controlling the speed of the vehicle when communications are restored from detected anomalous communications using the updated speed profile comprises controlling the speed of the vehicle based upon the updated current speed command.

4. The method of claim 2 , wherein controlling the speed of the vehicle when communications are restored from detected anomalous communications using the updated speed profile comprises controlling the speed of the vehicle based upon the updated future speed commands.

5. The method of claim 1 , wherein the future speed commands representing the predetermined controlled vehicle stop through the speed profile period are generated based upon at least one of a current position of the vehicle, a current velocity of the vehicle, a current acceleration of the vehicle, a braking capability of the vehicle, a preferred travel distance ahead of the vehicle, and a preferred driving speed ahead of the vehicle.

6. The method of claim 5 , wherein the current position of the vehicle comprises a current position of the vehicle in relation to a road geometry.

7. The method of claim 5 , wherein the current position of the vehicle comprises a current position of the vehicle in relation to another vehicle.

8. The method of claim 5 , wherein reducing the speed of the vehicle according to the future speed commands based upon the braking capability of the vehicle.

9. The method of claim 5 , wherein the preferred travel distance ahead of the vehicle is based upon a travel trajectory within a platoon of vehicles as communicated by a leader vehicle of the platoon of vehicles.

10. The method of claim 5 , wherein the preferred travel distance ahead of the vehicle is based upon tracked objects on the vehicle path at the time of detected anomalous communications, a lane geometry at the time of detected anomalous communications, and a worst case progression in front of the vehicle.

11. The method of claim 5 , wherein the preferred travel distance ahead of the vehicle is based upon tracked objects on the vehicle path at the time of detected anomalous communications, a lane geometry at the time of detected anomalous communications, and a threshold likelihood progression in front of the vehicle.

12. Method for controlling speed of a vehicle based upon control messages received through a communications device within the vehicle, the method comprising:

iteratively transmitting a control message from an autonomous controller within the vehicle through a communications device within the vehicle to the system providing propulsion to the vehicle, the control message comprising:

a current speed command representing an instantaneous desired speed for the vehicle; and

a plurality of future speed commands representing a controlled slowing of the vehicle, said plurality of future speed commands being based upon factors describing preferred operation of the vehicle to a stopped condition;

monitoring reception of the control message by the system providing propulsion to the vehicle;

when the monitored reception indicates normal communication, controlling the speed of the vehicle based solely upon the current speed command; and

when the monitored reception indicates anomalous communication, controlling the speed of the vehicle using a speed profile, comprising

determining a speed profile period containing a distance confirmed to be clear to traverse the vehicle at the time the monitored reception indicates anomalous communication, and

controlling the speed of the vehicle according to the current speed command at the time the monitored reception indicates anomalous communication until the vehicle has traversed a predetermined percentage of the speed profile period, and subsequently, reducing the speed of the vehicle based upon the plurality of future speed commands;

wherein the anomalous communication is determined by one of

irregular control message arrival times from the autonomous controller to the system providing propulsion to the vehicle, and

mismatched counter measurements between consecutive control messages sent by the autonomous controller to the system providing propulsion to the vehicle.

13. The method of claim 12 , wherein the factors describing preferred operation of the vehicle to a stopped condition comprise:

a position of the vehicle;

a velocity of the vehicle;

an acceleration of the vehicle;

a braking capability of the vehicle;

a preferred travel distance ahead of the vehicle; and

a preferred driving speed ahead of the vehicle.

14. Method for operating a vehicle within a platoon of vehicles utilizing vehicle-to-vehicle communication, the method comprising:

monitoring a travel trajectory from a leader vehicle of the platoon of vehicles comprising a relative position of the vehicle with respect to other vehicles within the platoon of vehicles;

within the vehicle, determining a control message comprising a current speed command and a plurality of future speed commands based upon the monitored travel trajectory;

transmitting the control message from an autonomous controller within the vehicle for receipt by a system providing propulsion to the vehicle;

monitoring reception of the control message by the system providing propulsion to the vehicle; and

when the monitored reception indicates anomalous communication, controlling the speed of the vehicle using a speed profile, comprising

determining a speed profile period containing a distance confirmed to be clear to traverse the vehicle at the time the monitored reception indicates anomalous communication, and

controlling the speed of the vehicle according to the current speed command at the time the monitored reception indicates anomalous communication until the vehicle has traversed a predetermined percentage of the speed profile period, and subsequently, reducing the speed of the vehicle based upon the plurality of future speed commands;

wherein the anomalous communication is determined by one of

irregular control message arrival times from the autonomous controller to the system providing propulsion to the vehicle, and

mismatched counter measurements between consecutive control messages sent by the autonomous controller to the system providing propulsion to the vehicle.