Control system for reducing internally generated frictional and inertial resistance to manual positioning of a surgical manipulator

• US 8,864,751 B2
• Filed: 09/08/2010
• Issued: 10/21/2014
• Est. Priority Date: 12/20/2005
• Status: Active Grant

• Current Assignee: Intuitive Surgical Operations, Inc. (Intuitive Surgical Holdings, LLC)
• Original Assignee: Intuitive Surgical Operations, Inc. (Intuitive Surgical Holdings, LLC)
• Inventors: Prisco, Giuseppe Maria, Larkin, David Q., Nowlin, William C.
• Primary Examiner(s): Thomson, William
• Assistant Examiner(s): LIPITZ, JEFFREY BRIAN
• Application Number:
  US12/877,263
• Publication Number:
  US 20110009880A1
• Time in Patent Office: 1,504 Days
• Field of Search: 606/1, 606/130, 700/245, 700/258, 318/268.1, 318/268.2, 3185681-56825
• US Class Current: 606/1
• CPC Class Codes: A61B 34/30 Surgical robots
• CPC Class Codes: A61B 34/32 operating autonomously
• CPC Class Codes: A61B 34/35 for telesurgery
• CPC Class Codes: A61B 34/37 Master-slave robots A61B34/35 takes precedence
• CPC Class Codes: A61B 34/70 Manipulators specially adapted for use in surgery
• CPC Class Codes: A61B 34/75 Manipulators having means for prevention or compensation of hand tremors
• CPC Class Codes: A61B 90/361 Image-producing devices, e.g. surgical cameras
• CPC Class Codes: B25J 9/1638 compensation for arm bending/inertia, pay load weight/inertia
• CPC Class Codes: B25J 9/1641 compensation for backlash, friction, compliance, elasticity in the joints
• CPC Class Codes: B25J 9/1689 Teleoperation
• CPC Class Codes: G05B 2219/41213 Lookup table for load, motor torque as function of actual position
• CPC Class Codes: G05B 2219/41426 Feedforward of torque
• CPC Class Codes: Y10S 901/02 Arm motion controller
• CPC Class Codes: Y10S 901/15 Jointed arm
• CPC Class Codes: Y10S 901/28 Joint
• CPC Class Codes: Y10S 901/30 End effector

Abstract

A robotic control system is placed in clutch mode so that a slave manipulator holding a surgical instrument is temporarily disengaged from control by a master manipulator in order to allow manual positioning of the surgical instrument at a surgical site within a patient. Control systems implemented in a processor compensate for internally generated frictional and inertial resistance experienced during the positioning, thereby making movement more comfortable to the mover, and stabler from a control standpoint. Each control system drives a joint motor in the slave manipulator with a saturated torque command signal which has been generated to compensate for non-linear viscous forces, coulomb friction, cogging effects, and inertia forces subjected to the joint, using estimated joint angular velocities, accelerations and externally applied torques generated by an observer in the control system from sampled displacement measurements received from a sensor associated with the joint.

Claims

1. A method implemented in a robotic system including a slave manipulator, a master manipulator, a master/slave control system configured to control movement of the slave manipulator in response to manipulation of the master manipulator, at least one friction and inertia compensating control system configured to generate a signal by processing measurements received from a corresponding one of a plurality of sensors of the slave manipulator to drive a corresponding one of a plurality of actuators of the slave manipulator so as to reduce effects of internally generated frictional and inertial resistance when at least a portion of the slave manipulator is being manually moved, the method comprising:

engaging the master/slave control system and disengaging the at least one friction and inertia compensating control system when the robotic system is in a first selectable mode; and

disengaging the master/slave control system and engaging the at least one friction and inertia compensating control system when the robotic system is in a second selectable mode.

2. The method according to claim 1, further comprising:

placing the robotic system in the first selectable mode when a switch is in a first state; and

placing the robotic system in the second selectable mode when the switch is in a second state.