Drop detection of ungrounded master controller for a surgical robot

A user interface device (UID) for a surgical robotic system, comprising:

• one or more contact sensors configured to generate contact data that indicates contact by a user of parts of the UID;
• one or more tracking sensors configured to generate motion data that indicates motions of the UID;
• a processor configured to:
• determine that the UID is not being held by the user for a duration greater than a time threshold based on the contact data:
• responsive to determining that the UID is not being held by the user for the duration greater than the time threshold, sense, from the one or more tracking sensors the motion data;
• determine a free-falling motion of the UID based on the motion data;
• and
• decouple the surgical robotic system from a movement of the UID in response to the determination that the UID is not being held by the user for the duration greater than the time threshold and the determination of the free-falling motion of the UID.

A surgical robotic system, comprising:

• an operating table;
• a plurality of robotic arms coupled to the operating table;
• a user interface device (UID) configured to:
• receive contact data from one or more contact sensors configured to sense contact by a user of part of the UID;
• determine whether the UID is held based on the contact data;
• responsive to determining that the UID is not held
• receive motion data from one or more tracking sensors configured to measure motions of the UID, and
• determine whether the UID is in a free-fall motion based on the motion data;
• and
• responsive to determining that the UID is held, generate an input command to one of the robotic arms based on the motions of the UID;
• and
• a computer communicatively coupled to the UID and the plurality of robotic arms, wherein the computer is configured to:
• receive the input command from the UID;
• and
• generate a control command to manipulate one of the robotic arms in response to the input command.