Robot system

A method of operating a robot, the method comprising:

• with at least one actuator, moving one or more movable parts of the robot;
• with a proximity sensor disposed on the one or more movable parts, generating first sensor data indicative of a distance between the proximity sensor and an external object;
• with a joint position sensor coupled to at least one actuator, generating second sensor data indicative of a speed of the one or more movable parts;
• stopping motion of the one or more movable parts in response to the second sensor data indicating that the speed exceeds a threshold speed;
• slowing but not stopping the motion of the one or more movable parts when the distance falls from a first distance that exceeds a first threshold distance to a second distance that is less than the first threshold distance and greater than a second threshold distance, the second threshold distance being less than the first threshold distance;
• stopping the motion of the one or more movable parts when the distance falls below the second threshold distance;
• with one or more processors, computing, based on a reading from a sensing element of force or torque, a dynamic model of the one or more movable parts to generate an estimated external force exerted on at least a tool end of the one or more movable parts, the sensing element of force or torque being different from the proximity sensor;
• slowing down a speed monitoring point to a set speed in response to the measured distance falling below the distance threshold, wherein the speed monitoring point is located at the tool end or on a tool attached to the tool end,
• stopping the one or more movable parts in response to the estimated external force exceeding a set limit, and
• stopping the one or more movable parts in response to the speed monitoring point moving faster than the speed limit.