Palletizing boxes

1. A method comprising:

positioning, by a robot, an object at an initial position adjacent to a target object location;

tilting, by the robot, the object at an angle relative to a ground plane;

shifting, by the robot, the object in a first direction from the initial position toward a first alignment position;

shifting, by the robot, the object in a second direction from the first alignment position toward a second alignment position; and

releasing, by the robot, the object from the robot to pivot the object toward the target object location.

2. The method of claim 1 , wherein the second direction is perpendicular to the first direction.

3. The method of claim 1 , wherein the object is a box.

4. The method of claim 3 , wherein positioning the box at the initial position comprises holding the box above the target object location without contacting an adjacent box.

5. The method of claim 3 , further comprising releasing the box such that the box abuts against one or more adjacent boxes.

6. The method of claim 3 , wherein the target object location is on a pallet that supports a plurality of boxes.

7. The method of claim 1 , further comprising obtaining sensor data by an optical sensor of the robot, and determining that the first alignment position satisfies a threshold alignment distance based on the sensor data.

8. The method of claim 7 , further comprising determining, by the robot, a first compensation distance in the first direction based on the sensor data, the first compensation distance compensating for a difference between an actual position of the object and a perceived position of the object by the robot.

9. The method of claim 1 , further comprising sensing, by the robot, a contact force on the object greater than a threshold, and halting shifting of the object in the second direction.

10. The method of claim 1 , further comprising receiving, by the robot, the target object location.

11. A robot comprising:

an arm comprising an end-effector configured to grasp an object;

data processing hardware; and

memory hardware in communication with the data processing hardware, the memory hardware storing instructions that when executed on the data processing hardware cause the data processing hardware to perform operations comprising:

positioning the object at an initial position adjacent to a target object location;

tilting the object at an angle relative to a ground plane;

shifting the object in a first direction from the initial position toward a first alignment position;

shifting the object in a second direction from the first alignment position toward a second alignment position; and

releasing the object from the robot to pivot the object toward the target object location.

12. The robot of claim 11 , wherein the second direction is perpendicular to the first direction.

13. The robot of claim 11 , further comprising an optical sensor configured to obtain sensor data, wherein the operations further comprise determining that the first alignment position satisfies a threshold alignment distance based on the sensor data.

14. The robot of claim 11 , wherein the operations further comprise sensing, by the robot, a contact force on the object greater than a threshold, and halting shifting of the object in the second direction.

15. The robot of claim 11 , wherein the operations further comprise receiving, by the robot, the target object location.

16. The robot of claim 11 , wherein the end-effector comprises a plurality of suction cups configured to apply a suction force to grasp the object.

17. The robot of claim 11 , further comprising:

an inverted pendulum body having a first end portion, a second end portion, and a plurality of joints, wherein the arm is coupled to the inverted pendulum body at a first joint of the plurality of joints; and

at least one leg having first and second ends, the first end coupled to the inverted pendulum body at a second joint of the plurality of joints.

18. The robot of claim 17 , further comprising a drive wheel rotatably coupled to the second end of the at least one leg and configured to move the robot according to rolling contact with the ground plane, and a counter-balance body disposed on the inverted pendulum body and configured to move relative to the inverted pendulum body.

19. The robot of claim 11 , wherein the object is a box, wherein the operations further comprise releasing the box such that the box abuts against one or more adjacent boxes.

20. The robot of claim 19 , wherein the target object location is on a pallet that supports a plurality of boxes.