Safe state to safe state navigation
Systems and methods are provided for navigating a host vehicle. In some embodiments, the system may include at least one processing device programmed to: receive at least one image representative of an environment of the host vehicle; determine a navigational action of the host vehicle; analyze the at least one image to identify a target vehicle in the environment of the host vehicle; determine a next-state distance between the host vehicle and the target vehicle that would result if the navigational action was taken; determine a maximum braking capability of the host vehicle, a maximum acceleration capability of the host vehicle, and a speed of the host vehicle; determine a stopping distance for the host vehicle; determine a speed of the target vehicle; and implement the navigational action if the determined stopping distance for the host vehicle is less than the next-state distance summed with a target vehicle travel distance.
1. A system for navigating a host vehicle, the system comprising:
at least one processor programmed to:
receive, from an image capture device, at least one image representative of an environment of the host vehicle;
determine, based on at least one driving policy, a planned navigational action for accomplishing a navigational goal of the host vehicle;
analyze the at least one image to identify a target vehicle in the environment of the host vehicle;
determine a next-state distance between the host vehicle and the target vehicle that would result if the planned navigational action was taken;
determine a maximum braking capability of the host vehicle, a maximum acceleration capability of the host vehicle, and a speed of the host vehicle;
determine a stopping distance for the host vehicle based on the maximum braking capability of the host vehicle, the maximum acceleration capability of the host vehicle, and the speed of the host vehicle;
determine a speed of the target vehicle and assume a maximum braking capability of the target vehicle based on at least one recognized characteristic of the target vehicle; and
implement the planned navigational action when the determined stopping distance for the host vehicle is less than the determined next-state distance summed together with a target vehicle travel distance determined based on the speed of the target vehicle and the assumed maximum braking capability of the target vehicle.
2. The system of claim 1 , wherein the stopping distance for the host vehicle includes an acceleration distance that corresponds to a distance the host vehicle can travel over a predetermined time period at the maximum acceleration capability of the host vehicle, with an initial speed corresponding to the determined speed of the host vehicle.
3. The system of claim 2 , wherein the predetermined time period is a reaction time associated with the host vehicle.
4. The system of claim 1 , wherein the target vehicle speed is determined based on analysis of the at least one image.
5. The system of claim 1 , wherein the target vehicle speed is determined based on analysis of an output from at least one of a LIDAR system or a RADAR system associated with the host vehicle.
6. The system of claim 1 , wherein the recognized characteristic of the target vehicle includes a vehicle type.
7. The system of claim 1 , wherein the recognized characteristic of the target vehicle is a vehicle size.
8. The system of claim 1 , wherein the recognized characteristic of the target vehicle includes a vehicle model.
9. The system of claim 1 , wherein the recognized characteristic of the target vehicle is determined based on analysis of the at least one image.
10. The system of claim 1 , wherein the at least one characteristic of the target vehicle is determined based on at least one of a LIDAR output or a RADAR output.
11. The system of claim 1 , wherein the planned navigational action includes at least one of a lane change maneuver, a merge maneuver, a passing maneuver, a follow distance reduction maneuver, or a maintain throttle action.
12. The system of claim 1 , wherein the at least one processor is configured to implement the planned navigational action if the determined stopping distance for the host vehicle is less, by at least a predetermined minimum distance, than the determined next-state distance summed together with a target vehicle travel distance, wherein the target vehicle travel distance is determined based on the speed of the target vehicle and the assumed maximum braking capability of the target vehicle.
13. The system of claim 12 , wherein the predetermined minimum distance corresponds to a predetermined separation distance to be maintained between the host vehicle and other vehicles.
14. A method for navigating a host vehicle, comprising:
receiving, from an image capture device, at least one image representative of an environment of the host vehicle;
determining, based on at least one driving policy, a planned navigational action for accomplishing a navigational goal of the host vehicle;
analyzing the at least one image to identify a target vehicle in the environment of the host vehicle;
determining a next-state distance between the host vehicle and the target vehicle that would result if the planned navigational action was taken;
determining a maximum braking capability of the host vehicle, a maximum acceleration capability of the host vehicle, and a speed of the host vehicle;
determining a stopping distance for the host vehicle based on the maximum braking capability of the host vehicle, the maximum acceleration capability of the host vehicle, and the speed of the host vehicle;
determining a speed of the target vehicle and assume a maximum braking capability of the target vehicle based on at least one recognized characteristic of the target vehicle; and
implementing the planned navigational action when the determined stopping distance for the host vehicle is less than the determined next-state distance summed together with a target vehicle travel distance determined based on the speed of the target vehicle and the assumed maximum braking capability of the target vehicle.
15. The method of claim 14 , wherein the stopping distance for the host vehicle includes an acceleration distance that corresponds to a distance the host vehicle can travel over a predetermined time period at the maximum acceleration capability of the host vehicle, with an initial speed corresponding to the determined speed of the host vehicle.
16. The method of claim 15 , wherein the predetermined time period is a reaction time associated with the host vehicle.
17. The method of claim 14 , wherein the target vehicle speed is determined based on analysis of the at least one image.
18. The method of claim 14 , wherein the target vehicle speed is determined based on analysis of an output from at least one of a LIDAR system or a RADAR system associated with the host vehicle.
19. The method of claim 14 , wherein the recognized characteristic of the target vehicle includes a vehicle type.
20. The method of claim 14 , wherein the recognized characteristic of the target vehicle is a vehicle size.
21. The method of claim 14 , wherein the recognized characteristic of the target vehicle includes a vehicle model.
22. The method of claim 14 , wherein the recognized characteristic of the target vehicle is determined based on analysis of the at least one image.
23. The method of claim 14 , wherein the at least one characteristic of the target vehicle is determined based on at least one of a LIDAR output or a RADAR output.
24. The method of claim 14 , wherein the planned navigational action includes at least one of a lane change maneuver, a merge maneuver, a passing maneuver, a follow distance reduction maneuver, or a maintain throttle action.
25. The method of claim 14 , further comprising:
implementing the planned navigational action when the determined stopping distance for the host vehicle is less, by at least a predetermined minimum distance, than the determined next-state distance summed together with a target vehicle travel distance, wherein the target vehicle travel distance is determined based on the speed of the target vehicle and the assumed maximum braking capability of the target vehicle.
26. The method of claim 25 , wherein the predetermined minimum distance corresponds to a predetermined separation distance to be maintained between the host vehicle and other vehicles.