Estimating joint friction and tracking error of a robotics end effector
AssigneeVerb Surgical Inc.
InventorAlireza Hariri
Life of this patent
Estimating the term…
Abstract
A computerized method for estimating joint friction in a joint of a robotic wrist of an end effector. Sensor measurements of force or torque in a transmission that mechanically couples a robotic wrist to an actuator, are produced. Joint friction in a joint of the robotic wrist that is driven by the actuator is computed by applying the sensor measurements of force or torque to a closed form mathematical expression that relates transmission force or torque variables to a joint friction variable. A tracking error of the end effector is also computed, using a closed form mathematical expression that relates the joint friction variable to the tracking error. Other aspects are also described and claimed.
Claims18
A computerized method for estimating joint friction in a joint of a robotic wrist of an end effector, the method comprising the following operations performed by a computer system:
- producing sensor measurements of force or torque in a transmission that mechanically couples the robotic wrist to an actuator, wherein the sensor measurements are cable force measurements;
- computing joint friction in the joint of the robotic wrist that is driven by the actuator, based on the cable force measurements;
- and
- performing control tasks using the computed joint friction to control movement of the end effector, by generating one or more control signals which control how the actuator is energized to move the robotic wrist so that movement of the end effector mimics movement of a user input device.
An article of manufacture comprising a computer-readable storage medium having stored therein instructions that configure a processor to perform a method comprising:
- producing sensor measurements of force or torque in a transmission, wherein the transmission mechanically couples a robotic wrist of an end effector to an actuator so the actuator can drive a joint of the robotic wrist and the sensor measurements are cable force measurements;
- computing joint friction in the joint of the robotic wrist based on the cable force measurements;
- and
- performing control tasks to control movement of the end effector, by generating one or more control signals which control how the actuator is energized to move the robotic wrist so that movement of the end effector mimics movement of a user input device.
Dependencies are inferred from the claim text.