Medical robotic system with sliding mode control

摘要

A medical robotic system has a joint coupled to medical device or a slave manipulator or robotic arm adapted to hold and/or move the medical device for performing a medical procedure, and a control system for controlling movement of the joint according to user manipulation of a master manipulator. The control system includes at least one joint controller having a sliding mode control for reducing stick-slip behavior on its controlled joint during fine motions of the joint. The sliding mode control computes a distance to a sliding surface, computes a reaching law gain, and processes the distance and reaching law gain to generate a sliding mode control action that is in absolute value less that a maximum desired feedback control action. The sliding mode control action is then further processed to generate a feedback torque command for the joint motor.

主权项

1. A medical robotic system comprising:
a joint; and a controller programmed to use sliding mode control for controlling movement of the joint by: computing a sigma value using a position error associated with commanded movement of the joint; computing a reaching law gain as a monotonic mathematical function of the absolute value of the sigma value; computing a sliding mode control action using a product of the sigma value and the reaching law gain; and commanding the joint to be moved at least partially in response to the sliding mode control action.