Palletizing boxes
A method for palletizing by a robot includes positioning an 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.
1. A method of placing an object grasped by a mobile robot at a target location, the method comprising:
receiving, from a sensor system of the mobile robot, sensor data;
determining based, at least in part on the sensor data, a target object location and an initial position adjacent to the target object location;
positioning, by the mobile robot, an object grasped by a suction gripper of the mobile robot at the initial position;
tilting, by the mobile robot, the object at an angle relative to a ground plane;
shifting, by the mobile robot, the object from the initial position toward an alignment position; and
releasing, by the mobile robot, the object from the suction gripper of the mobile robot to pivot the object toward the target object location.
2. The method of claim 1 , wherein the object is a box.
3. The method of claim 2 , wherein positioning the box at the initial position comprises holding the box above the target object location without contacting an adjacent box.
4. The method of claim 2 , further comprising releasing the box such that the box abuts against one or more adjacent boxes.
5. The method of claim 2 , wherein the target object location is on a pallet that supports a plurality of boxes.
6. The method of claim 1 , further comprising determining that the alignment position satisfies a threshold alignment distance based on the sensor data.
7. The method of claim 6 , further comprising determining, by the mobile robot, a compensation distance based on the sensor data, the compensation distance compensating for a difference between an actual position of the object and a perceived position of the object by the mobile robot.
8. The method of claim 1 , further comprising sensing, by the mobile robot, a contact force on the object greater than a threshold, and halting shifting of the object in response to sensing the contact force greater than the threshold.
9. The method of claim 1 , further comprising receiving, by the robot, the target object location.
10. The method of claim 1 , wherein determining an initial position adjacent to the target object location comprises:
determining, based on the sensor data, a first offset in a first direction;
determining, based on the sensor data, a second offset in a second direction, wherein the second direction is different than the first direction; and
determining the initial position based, at least in part, on the first offset and the second offset.
11. The method of claim 1 , further comprising:
determining a movement vector from the initial position to the target object position,
wherein shifting the object from the initial position toward an alignment position comprises shifting the object along the movement vector.
12. A mobile robot comprising:
a mobile base;
an arm coupled to the mobile base, the arm comprising a suction-based gripper configured to grasp an object;
a sensor system comprising one or more sensors configured to sense objects in an environment of the mobile robot;
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:
determining based, at least in part, on sensor data received from the sensor system, a target object location and an initial position adjacent to the target object location;
positioning an object grasped by the suction-based gripper at the initial position;
tilting the object at an angle relative to a ground plane;
shifting the object from the initial position toward an alignment position; and
releasing the object from the suction-based gripper of the mobile robot to pivot the object toward the target object location.
13. The mobile robot of claim 12 , wherein the operations further comprise determining that the first alignment position satisfies a threshold alignment distance based on the sensor data.
14. The mobile robot of claim 12 , wherein the operations further comprise sensing, by the mobile robot, a contact force on the object greater than a threshold, and halting shifting of the object in response to sensing the contact force greater than the threshold.
15. The mobile robot of claim 12 , 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.
16. The mobile robot of claim 15 , further comprising a drive wheel rotatably coupled to the second end of the at least one leg and configured to move the mobile 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.
17. The mobile robot of claim 12 , 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.
18. The mobile robot of claim 17 , wherein the target object location is on a pallet that supports a plurality of boxes.
19. The mobile robot of claim 12 , wherein determining an initial position adjacent to the target object location comprises:
determining, based on the sensor data, a first offset in a first direction;
determining, based on the sensor data, a second offset in a second direction, wherein the second direction is different than the first direction; and
determining the initial position based, at least in part, on the first offset and the second offset.
20. The mobile robot of claim 12 , wherein the operations further comprise:
determining a movement vector from the initial position to the target object position,
wherein shifting the object from the initial position toward an alignment position comprises shifting the object along the movement vector.