System and apparatus for external torque observation and compensation for surgical robotic arm

A surgical robotic arm comprising:

• a link;
• an actuator configured to move the link;
• a torque sensor configured to measure torque imparted on the link to obtain a measured torque value;
• and
• a controller configured to:
• determine an environmental torque value based on the measured torque value;
• detect a collision based on the environmental torque value being above a first threshold;
• and
• enter a collision state in response to the environmental torque value being above the first threshold, wherein while in the collision state, the controller is further configured to determine the collision state is terminated based on the environmental torque value being below a second threshold.

A surgical robotic arm comprising:

• a link;
• an actuator configured to move the link;
• a torque sensor configured to measure torque imparted on the link to obtain a measured torque value;
• and
• a controller configured to:
• determine an environmental torque value based on the measured torque value;
• detect a collision based on the environmental torque value being above a first threshold;
• enter a collision state in response to the environmental torque value being above the first threshold;
• and
• exit the collision state in response to the environmental torque value being below a second threshold.

A method for detecting collision of a surgical robotic arm, the method comprising:

• measuring torque imparted on at least one movable link of the surgical robotic arm to obtain a measured torque value;
• determining an environmental torque value based on the measured torque value;
• detecting a collision based on the environmental torque value being above a first threshold;
• entering the surgical robotic arm into a collision state in response to the environmental torque value being above the first threshold;
• and
• while in the collision state, determining the collision state is terminated based on the environmental torque value being below a second threshold.