Impedance Control: An Approach to Manipulation: Part II—Implementation

Abstract

This three-part paper presents an approach to the control of dynamic interaction between a manipulator and its environment. Part I presented the theoretical reasoning behind impedance control. In Part II the implementation of impedance control is considered. A feedback control algorithm for imposing a desired cartesian impedance on the end-point of a nonlinear manipulator is presented. This algorithm completely eliminates the need to solve the “inverse kinematics problem” in robot motion control. The modulation of end-point impedance without using feedback control is also considered, and it is shown that apparently “redundant” actuators and degrees of freedom such as exist in the primate musculoskeletal system may be used to modulate end-point impedance and may play an essential functional role in the control of dynamic interaction.

Human motion in cooperative tasks: Moving object case study

“…As for the interaction with the environment, Hogan [7], [8] shows that human muscle architecture allows controlling the impedance of the arm, and that impedance must be adapted to the task. There is strong evidence [9] that human indeed adapts its impedance to the task, but feedback must also be used [9]).…”

Continuous critic learning for robot control in physical human-robot interaction

“…Impedance control is first introduced in [7] to achieve certain desirable impedance and impose a desirable dynamic behavior to the interaction between the robot and environment. To apply the impedance control, we need to find a desired impedance model in the cartesian space as follows…”

“…In the literature of interaction control, two major frameworks are widely recognized, which are position/force control [5], [8], [12] and impedance control [7]. Compared to the former one, impedance control is more acceptable as it does not require the full decomposition of force and tracking trajectory.…”

Neural networks impedance control of robots interacting with environments

“…The second is impedance control [6], which is aimed at developing a relationship between the contact force and position instead of controlling force or position separately. By specifying the relationship between the contact force and position, impedance control ensures that the robot is able to maneuver in a constrained environment while maintaining appropriate contact force [1].…”