Autonomous approach and object pickup

An autonomous vehicle, comprising:

• one or more lift elements positioned on a side of the autonomous vehicle;
• at least one horizontal force sensor configured to detect a horizontal force in a direction toward the side of the autonomous vehicle;
• at least one vertical force sensor configured to detect a downward force on the one or more lift elements;
• and
• a control system configured to:
• determine that the one or more lift elements of the autonomous vehicle are partially positioned under a particular object when instructions to pick up an object are received;
• based on determining that the one or more lift elements of the autonomous vehicle are partially positioned under the particular object when the instructions are received, identify the particular object as the object to be picked up;
• cause the autonomous vehicle to move along an approach path toward the object;
• based on sensor data from the at least one horizontal force sensor indicating a horizontal force from the object on the autonomous vehicle, determine that the one or more lift elements are positioned under the object;
• cause the one or more lift elements to raise the object;
• and
• based on sensor data from the at least one vertical force sensor indicating a stable downward force from the object on the one or more lift elements, determine that the object is lifted off of a ground surface.

A non-transitory computer readable medium having stored therein instructions, that when executed by a control system of an autonomous vehicle, cause the control system to perform functions comprising:

• receiving instructions to pick up an object with one or more lift elements of the autonomous vehicle;
• determining that the one or more lift elements of the autonomous vehicle are partially positioned under a particular side of a particular object when the instructions are received;
• based on determining that the one or more lift elements of the autonomous vehicle are partially positioned under the particular side of the particular object when the instructions are received, identifying the particular object as the object to be picked up;
• determining an approach path toward the particular object for the autonomous vehicle to follow to place the one or more lift elements of the autonomous vehicle under the particular side of the particular object;
• causing, by the control system, the autonomous vehicle to move along the determined approach path toward the particular object;
• determining that the one or more lift elements of the autonomous vehicle are placed under the particular side of the particular object;
• and
• causing the autonomous vehicle to lift the particular object with the one or more lift elements.