Hard stop protection system and method

An articulable system comprising:

• a joint mechanism comprising a joint and having a mechanical limit, the mechanical limit defining a mechanical limit location;
• an actuator physically coupled to the joint mechanism;
• a sensor system associated with the joint mechanism and configured to sense a joint state of the joint, the joint state including at least one of a speed, a position, or a direction of movement of the joint;
• and
• a controller in communication with the sensor system and the actuator, the controller configured to, when in a mode in which the actuator at least partially assists movement of the joint due to a first externally applied force:
• determine a joint velocity threshold based on the joint state and a velocity profile, wherein the velocity profile defines a plurality of velocity criteria each associated with at least one joint position of the joint and relative to the mechanical limit location;
• and
• command the actuator to resist movement of the joint due to a second externally applied force in response to determining that:
• (i) the joint velocity threshold is exceeded, and (ii) the joint is moving toward the mechanical limit location.