• Home
  •  >
  • Robotica
  •  >
  • Volume 29
  •  >
  • Issue 04
  •  >
  • The relationship between controlled joint torque and end-effector force in underactuated robotic systems

Robotica

Table of Contents - July 2011 - Volume 29, Issue 04  

Articles

The relationship between controlled joint torque and end-effector force in underactuated robotic systems

Jaeheung Parka1 c1

a1 Seoul National University, 864-1 Iui-dong, Yeongtong-gu, Suwon-si, Gyeonggi-do, Korea

SUMMARY

The generalized Jacobian matrix was introduced for dealing with end-effector control in space robots. One of the applications of this Jacobian is to be used in Jacobian transpose control to generate joint torques given end-effector position error. It would be misleading, however, to consider the transpose of this Jacobian as a mapping from end-effector force/moment to controlled joint torques for underactuated systems or floating base robots. This paper explains why it does not represent the mapping and provides a simple example. Later, the correct mapping is provided using the dynamically consistent Jacobian inverse and then a method to compute the actuated-joint torques is explained given the desired end-effector force. Finally, the effect of using the generalized Jacobian in the Jacobian transpose control is analyzed.

(Received July 16 2010)

(Online publication August 16 2010)

KEYWORDS:

  • Generalized Jacobian;
  • Space robot;
  • Underactuation;
  • Torque–force relationship

Correspondence:

c1 Corresponding author. E-mail: park73@snu.ac.kr