Robot planning

1. A method performed by a robotics control system comprising one or more computers, the method comprising:

receiving, for a robot, an initial plan specifying a path and a local trajectory;

receiving an updated observation of an environment of the robot;

generating an initial modified local trajectory for the robot based on the updated observation in the environment of the robot, wherein the initial modified local trajectory extends outside of a boundary of a workspace footprint for the robot at the time that the initial modified local trajectory is generated, the workspace footprint defining a physical volume within a workcell for the robot to perform a task;

repeatedly following the initial modified local trajectory that extends outside the footprint of the robot while generating a modified global path for the robot that remains entirely within the footprint of the robot until the modified global path has been generated, wherein generating the modified global path comprises:

obtaining data representing the workspace footprint for the robot, and

generating the modified global path to avoid causing the robot to cross a boundary of the physical volume defined by the workspace footprint;

determining that the modified global path has been generated; and

causing the robot to switch from following the initial modified local trajectory to following the modified global path for the robot.

2. The method of claim 1 , wherein the robotics control system has a first time constraint on computing local trajectories and a second time constraint on computing modified global paths, wherein the second time constraint is larger than the first time constraint.

3. The method of claim 2 , wherein the robotics control system enters a fault state if the first time constraint is violated when not computing a modified global path.

4. The method of claim 3 , wherein the robotics control system enters a fault state if the second time constraint is violated when computing the modified global path.

5. The method of claim 1 , wherein repeatedly following the initial modified local trajectory for the robot while generating a modified global path for the robot comprises bypassing a process for computing local trajectories from sensor observations.

6. The method of claim 1 , wherein the workspace footprint is precomputed offline for the robot.

7. The method of claim 1 , wherein generating the modified global path to avoid causing the robot to cross the boundary of the physical volume defined by the workspace footprint comprises generating a modified global path that causes the robot to remain within the physical volume defined by the workspace footprint.

8. The method of claim 1 , wherein generating the modified global path to avoid causing the robot to cross the boundary of the physical volume defined by the workspace footprint comprises generating a modified global path that causes the robot to remain outside the physical volume defined by the workspace footprint.

9. The method of claim 1 , wherein the workspace footprint is computed online in real-time for the robot.

10. The method of claim 1 , wherein the modified global path extends from a point along the initial modified local trajectory.

11. A robotics control system comprising:

one or more processors; and

a non-transitory storage medium storing computer instructions operable to cause the one or more processors to perform operations comprising:

receiving, for a robot, an initial plan specifying a path and a local trajectory;

receiving an updated observation of an environment of the robot;

generating an initial modified local trajectory for the robot based on the updated observation in the environment of the robot, wherein the initial modified local trajectory extends outside of a boundary of a workspace footprint for the robot at the time that the initial modified local trajectory is generated, the workspace footprint defining a physical volume within a workcell for the robot to perform a task;

repeatedly following the initial modified local trajectory that extends outside the footprint of the robot while generating a modified global path for the robot that remains entirely within the footprint of the robot until the modified global path has been generated, wherein generating the modified global path comprises:

obtaining data representing the workspace footprint for the robot, and

generating the modified global path to avoid causing the robot to cross a boundary of the physical volume defined by the workspace footprint;

determining that the modified global path has been generated; and

causing the robot to switch from following the initial modified local trajectory to following the modified global path for the robot.

12. The robotics control system of claim 11 , wherein the robotics control system has a first time constraint on computing local trajectories and a second time constraint on computing modified global paths, wherein the second time constraint is larger than the first time constraint.

13. The robotics control system of claim 12 , wherein the robotics control system enters a fault state if the first time constraint is violated when not computing a modified global path.

14. The robotics control system of claim 13 , wherein the robotics control system enters a fault state if the second time constraint is violated when computing the modified global path.

15. The robotics control system of claim 11 , wherein repeatedly following the initial modified local trajectory for the robot while generating a modified global path for the robot comprises bypassing a process for computing local trajectories from sensor observations.

16. The robotics control system of claim 11 , wherein the workspace footprint is precomputed offline for the robot.

17. The robotics control system of claim 11 , wherein generating the modified global path to avoid causing the robot to cross the boundary of the physical volume defined by the workspace footprint comprises generating a modified global path that causes the robot to remain within the physical volume defined by the workspace footprint.

18. The robotics control system of claim 11 , wherein generating the modified global path to avoid causing the robot to cross the boundary of the physical volume defined by the workspace footprint comprises generating a modified global path that causes the robot to remain outside the physical volume defined by the workspace footprint.

19. The robotics control system of claim 11 , wherein the workspace footprint is computed online in real-time for the robot.

20. A non-transitory computer-readable storage medium comprising instructions that, when executed by one or more computers, cause the one or more computers to perform operations comprising:

receiving, for a robot, an initial plan specifying a path and a local trajectory;

receiving an updated observation of an environment of the robot;

generating an initial modified local trajectory for the robot based on the updated observation in the environment of the robot, wherein the initial modified local trajectory extends outside of a boundary of a workspace footprint for the robot at the time that the initial modified local trajectory is generated, the workspace footprint defining a physical volume within a workcell for the robot to perform a task;

repeatedly following the initial modified local trajectory that extends outside the footprint of the robot while generating a modified global path for the robot that remains entirely within the footprint of the robot until the modified global path has been generated, wherein generating the modified global path comprises:

obtaining data representing the workspace footprint for the robot, and

generating the modified global path to avoid causing the robot to cross a boundary of the physical volume defined by the workspace footprint;

determining that the modified global path has been generated; and

causing the robot to switch from following the initial modified local trajectory to following the modified global path for the robot.