System and method for monitoring a moving vehicle

1. A system comprising:

an unmanned vehicle configured to monitor a second vehicle moving along a route, the unmanned vehicle comprising:

a communication module configured to enable a wireless communication link between the unmanned vehicle and the second vehicle for notifying the second vehicle of a hazardous condition;

a speed control unit in communication with the processing unit and configured to adjust a guide speed and a position of the unmanned vehicle such that the unmanned vehicle travels ahead of the second vehicle by at least a leading distance;

a sensor system configured to detect the hazardous condition along the route ahead of the unmanned vehicle; and

a processing unit configured to:

determine a braking distance for the second vehicle in response to a current speed of the second vehicle, wherein the braking distance characterizes a travel distance that the second vehicle will move from an initial location at which braking is initiated to a final location at which the second vehicle stops moving; and

determine the leading distance for the unmanned vehicle based on the braking distance, wherein the leading distance is greater than the braking distance by an additional travel distance of the vehicle determined by a processing overhead time needed for the processing unit to detect and classify the hazardous condition and a notification overhead time needed to notify the second vehicle of the hazardous condition via the wireless communication link.

2. The system of claim 1 wherein the processing unit is further configured to determine the braking distance based on at least the current speed, an elevation variability of the route, and a mass of the second vehicle.

3. The system of claim 1 wherein the current speed is a first current speed, the braking distance is a first braking distance, the leading distance is a first leading distance, and wherein:

the processing unit is further configured to:

determine a second braking distance for the second vehicle in response to a second current speed of the second vehicle, the second current speed differing from the first current speed; and

determine a second leading distance for the unmanned vehicle based on the second braking distance; and

the speed control unit is further configured to adjust the guide speed and position of the unmanned vehicle such that the unmanned travels ahead of the second vehicle by at least the second leading distance.

4. The system of claim 1 wherein the wireless communication link is established based on a dedicated short-range communications (DSRC) technology.

5. The system of claim 1 wherein the hazardous condition is an obstacle on the route ahead of the second vehicle, and the sensor system includes a radar detection system for detecting the obstacle.

6. The system of claim 1 wherein the hazardous condition is an overspeed condition of the second vehicle, and wherein:

the processing unit is further configured to detect when the current speed of the second vehicle is greater than an allowable speed for the second vehicle at a future location of the second vehicle along the route; and

the communication module is further configured to notify the second vehicle of the allowable speed for the future location.

7. The system of claim 1 wherein:

the hazardous condition is a deviation from the route;

the unmanned vehicle further comprises a memory element in communication with the processing unit, the memory element having predetermined route information for the route stored therein;

the processing unit is further configured to detect the deviation from the route based at least in part on the predetermined route information; and

the communication module is further configured to notify the second vehicle of the deviation via the wireless communication link.

8. The system of claim 7 wherein:

the processing unit is further configured to determine a trajectory path for the second vehicle in response to the deviation; and

the speed control unit is further configured to adapt the position of the unmanned vehicle such that the unmanned vehicle travels ahead of the second vehicle along the trajectory path.

9. The system of claim 8 wherein the communication module is further configured to redirect the second vehicle from the trajectory path to the route.

10. The system of claim 1 wherein:

the unmanned vehicle further comprises a memory element in communication with the processing unit, the memory element having predetermined route information for the route stored therein;

when no hazardous conditions are detected by the sensor system, the processing unit is further configured to determine an optimal speed for the second vehicle at a future location based at least in part on the predetermined route information; and

the communication module is further configured to notify the second vehicle of the optimal speed for the future location via the wireless communication link.

11. The system of claim 1 wherein:

the unmanned vehicle is a first unmanned vehicle, and the first unmanned vehicle further comprises:

a battery for providing electrical energy to enable movement of the unmanned vehicle; and

a battery monitor circuit coupled with the battery and configured to monitor a battery output voltage, wherein when the battery output voltage drops below a threshold value, the communication module is configured to send a trigger signal to the second vehicle via the wireless communication link; and

the system further comprises a second unmanned vehicle residing on the second vehicle, the second unmanned vehicle being configured to replace the first unmanned vehicle in response to receipt of the trigger signal at the second vehicle.

12. A method utilizing an unmanned vehicle to monitor a second vehicle moving along a route, the method being performed by the unmanned vehicle, and the method comprising:

determining a braking distance for the second vehicle in response to a current speed of the second vehicle, the braking distance characterizing a travel distance that the second vehicle will move from an initial location at which braking is initiated to a final location at which the second vehicle stops moving;

determining a leading distance of the unmanned vehicle with respect to the second vehicle based on the braking distance, wherein the leading distance is greater than the braking distance by an additional travel distance of the second vehicle corresponding to a processing overhead time required by the unmanned vehicle to detect the hazardous condition and a notification overhead time required by the unmanned vehicle to notify the second vehicle of the hazardous condition via a wireless communication link;

adjusting a guide speed and position of the unmanned vehicle such that the unmanned vehicle travels ahead of the second vehicle by at least the leading distance;

detecting a hazardous condition along the route ahead of the unmanned vehicle; and

notifying the second vehicle of the hazardous condition via the wireless communication link.

13. The method of claim 12 further comprising determining the braking distance based on at least the current speed, an elevation variability of the route, and a mass of the second vehicle.

14. The method of claim 12 wherein the current speed is a first current speed at a first instant in time, the braking distance is a first braking distance, the leading distance is a first leading distance, and the method further comprises:

determining a second braking distance for the second vehicle in response to a second current speed of the second vehicle, the current speed differing from the first current speed;

determining a second leading distance for the unmanned vehicle based on the second braking distance; and

adjusting the guide speed and position of the unmanned vehicle such that the unmanned vehicle travels ahead of the second vehicle by at least the second leading distance.

15. The method of claim 12 wherein the unmanned vehicle further includes a radar detection system, the hazardous condition comprises an obstacle on the route ahead of the second vehicle, and the detecting operation comprises transmitting radar signals ahead of the unmanned vehicle via the radar detection system and receiving reflected radar signals, the reflected radar signals indicating the presence of the obstacle.

16. The method of claim 12 wherein the hazardous condition is an overspeed condition of the second vehicle, and the detecting operation comprises:

determining when the current speed of the second vehicle is greater than an allowable speed for the second vehicle at a future location of the second vehicle along the route; and

notifying the second vehicle of the allowable speed for the future location.

17. The method of claim 12 wherein the unmanned vehicle includes a memory element having predetermined route information for the route stored therein, the hazardous condition is a deviation of the second vehicle from the route, and the detecting operation comprises:

identifying the deviation from the route based at least in part on the predetermined route information;

notifying the second vehicle of the deviation via the wireless communication link;

determining a trajectory path for the second vehicle in response to the deviation; and

adapting the position of the unmanned vehicle such that the unmanned vehicle travels ahead of the second vehicle along the trajectory path.

18. The method of claim 12 wherein the unmanned vehicle further comprises a memory element in communication with the processing unit, the memory element having predetermined route information for the route stored therein, when no hazardous conditions are detected, the method further comprises:

determining an optimal speed for the second vehicle at a future location based at least in part on the predetermined route information; and

notifying the second vehicle of the optimal speed for the future location via the wireless communication link.

19. The method of claim 12 wherein the unmanned vehicle includes a battery for providing electrical energy to enable the unmanned vehicle to travel ahead of the second vehicle, and the method further comprises:

monitoring unmanned vehicle to identify a trigger condition;

when the trigger condition is detected, sending a trigger signal to the second vehicle via the wireless communication link; and

replacing the unmanned vehicle with a second unmanned vehicle in response to receipt of the trigger signal at the second vehicle.