Robotica

Table of Contents - 2008 - Volume 26, Issue 01  

Article

Disturbance rejection by online ZMP compensation

Vadakkepat Prahlada1 c1, Goswami Dipa1 and Chia Meng-Hweea1

a1 Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576

SUMMARY

A novel method of Zero-Moment-Point (ZMP) compensation is proposed to improve the stability of locomotion of a biped, which is subjected to disturbances. A compensating torque is injected into the ankle-joint of the foot of the robot to improve stability. The value of the compensating torque is computed from the reading of the force sensors located at the four corners of each foot. The effectiveness of the method is verified on a humanoid robot, MANUS-I. With the compensation technique, the robot successfully rejected disturbances in different forms. It carried an additional weight of 390 gm (17% of body weight) while walking. Also, it walked up a 10° slope and walked down a 3° slope.

(Received May 08 2007)

(Online publication June 25 2007)

KEYWORDS:

  • Biped locomotion;
  • Humanoid;
  • Zero-Moment-Point compensation

Correspondence:

c1 Corresponding author. E-mail: prahlad@ieee.org