Partial manual control state for automated vehicle navigation system

1. A method for control of a moving vehicle comprising:

detecting an alarm condition, said step of detecting an alarm condition comprising detecting that said vehicle has become unstable;

determining, by a controller, a radius of a curved path that said vehicle is following at the time when said alarm condition is detected; and

in response to said alarm condition, maintaining the curved path based at least in part on data received via one or more GPS receivers.

2. The method of claim 1 wherein said step of maintaining the curved path comprises maintaining forward motion of said vehicle.

3. The method of claim 1 further comprising:

placing said vehicle in a manual control state in response to an operator control input.

4. The method of claim 1 wherein said radius is determined based on data from at least one sensor.

5. The method of claim 1 , further comprising:

receiving a GPS signal via one or more GPS receivers; and

detecting an alarm condition when a loss of the GPS signal occurs.

6. A method for control of a moving vehicle comprising:

detecting an alarm condition, said step of detecting an alarm condition comprising detecting that said vehicle has become unstable; and

determining, by a controller, a radius of curvature of said vehicle when said alarm condition was detected;

in response to said alarm condition, maintaining said radius of curvature based at least in part on data received via one or more GPS receivers.

7. The method of claim 6 wherein said step of maintaining said radius of curvature comprises maintaining forward motion of said vehicle.

8. The method of claim 6 further comprising:

placing said vehicle in a manual control state in response to an operator control input.

9. The method of claim 6 further comprising:

setting steering of said vehicle to straight before said maintaining said radius of curvature if said determined radius of curvature is greater than a threshold.

10. A vehicle comprising:

vehicle controls for controlling said vehicle;

an automated navigation system for directing said vehicle controls;

a manual control system for directing said vehicle controls;

at least one sensor for detecting at least one parameter of said vehicle;

one or more GPS receivers; and

an override control unit for:

receiving data from said at least one sensor;

determining a radius of a curved path that said vehicle is following when an alarm condition is detected; and

directing said vehicle controls to maintain the curved path based at least in part on data received via the one or more GPS receivers;

wherein said alarm condition is a result of vehicle instability.

11. The system of claim 10 , wherein said alarm condition is a result of a malfunction of said at least one sensor.

12. The system of claim 10 , further comprising an operator control sensor for detecting operator control.

13. The system of claim 10 , wherein said override control unit further directs said vehicle controls to maintain forward motion of said vehicle.

14. An apparatus for control of a moving vehicle comprising:

means for detecting an alarm condition, said means for detecting an alarm condition further comprising means for detecting vehicle instability;

means for determining a radius of a curved path that said vehicle is following at the time when said alarm condition is detected; and

means for maintaining the curved path based at least in part on data received via one or more GPS receivers, in response to said alarm condition.

15. The apparatus claim 14 wherein said means for maintaining the curved path comprises means for maintaining forward motion of said vehicle.

16. The apparatus of claim 14 further comprising:

means for placing said vehicle in a manual control state in response to an operator control input.

17. The apparatus of claim 14 further comprising:

means for steering of said vehicle straight before said maintaining the curved path if said determined radius is greater than a threshold.